llvm-project/llvm/lib/Target/PowerPC/PPCISelLowering.h

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//===-- PPCISelLowering.h - PPC32 DAG Lowering Interface --------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines the interfaces that PPC uses to lower LLVM code into a
// selection DAG.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_LIB_TARGET_POWERPC_PPCISELLOWERING_H
#define LLVM_LIB_TARGET_POWERPC_PPCISELLOWERING_H
#include "PPC.h"
#include "PPCInstrInfo.h"
#include "PPCRegisterInfo.h"
#include "llvm/CodeGen/CallingConvLower.h"
#include "llvm/CodeGen/SelectionDAG.h"
#include "llvm/Target/TargetLowering.h"
namespace llvm {
namespace PPCISD {
enum NodeType : unsigned {
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// Start the numbering where the builtin ops and target ops leave off.
FIRST_NUMBER = ISD::BUILTIN_OP_END,
/// FSEL - Traditional three-operand fsel node.
///
FSEL,
/// FCFID - The FCFID instruction, taking an f64 operand and producing
/// and f64 value containing the FP representation of the integer that
/// was temporarily in the f64 operand.
FCFID,
/// Newer FCFID[US] integer-to-floating-point conversion instructions for
/// unsigned integers and single-precision outputs.
FCFIDU, FCFIDS, FCFIDUS,
/// FCTI[D,W]Z - The FCTIDZ and FCTIWZ instructions, taking an f32 or f64
/// operand, producing an f64 value containing the integer representation
/// of that FP value.
FCTIDZ, FCTIWZ,
/// Newer FCTI[D,W]UZ floating-point-to-integer conversion instructions for
/// unsigned integers.
FCTIDUZ, FCTIWUZ,
/// Reciprocal estimate instructions (unary FP ops).
FRE, FRSQRTE,
// VMADDFP, VNMSUBFP - The VMADDFP and VNMSUBFP instructions, taking
// three v4f32 operands and producing a v4f32 result.
VMADDFP, VNMSUBFP,
/// VPERM - The PPC VPERM Instruction.
///
VPERM,
/// The CMPB instruction (takes two operands of i32 or i64).
CMPB,
/// Hi/Lo - These represent the high and low 16-bit parts of a global
/// address respectively. These nodes have two operands, the first of
/// which must be a TargetGlobalAddress, and the second of which must be a
/// Constant. Selected naively, these turn into 'lis G+C' and 'li G+C',
/// though these are usually folded into other nodes.
Hi, Lo,
/// The following two target-specific nodes are used for calls through
/// function pointers in the 64-bit SVR4 ABI.
/// OPRC, CHAIN = DYNALLOC(CHAIN, NEGSIZE, FRAME_INDEX)
/// This instruction is lowered in PPCRegisterInfo::eliminateFrameIndex to
/// compute an allocation on the stack.
DYNALLOC,
/// GlobalBaseReg - On Darwin, this node represents the result of the mflr
/// at function entry, used for PIC code.
GlobalBaseReg,
/// These nodes represent the 32-bit PPC shifts that operate on 6-bit
/// shift amounts. These nodes are generated by the multi-precision shift
/// code.
SRL, SRA, SHL,
/// The combination of sra[wd]i and addze used to implemented signed
/// integer division by a power of 2. The first operand is the dividend,
/// and the second is the constant shift amount (representing the
/// divisor).
SRA_ADDZE,
/// CALL - A direct function call.
/// CALL_NOP is a call with the special NOP which follows 64-bit
/// SVR4 calls.
CALL, CALL_NOP,
/// CHAIN,FLAG = MTCTR(VAL, CHAIN[, INFLAG]) - Directly corresponds to a
/// MTCTR instruction.
MTCTR,
/// CHAIN,FLAG = BCTRL(CHAIN, INFLAG) - Directly corresponds to a
/// BCTRL instruction.
BCTRL,
/// CHAIN,FLAG = BCTRL(CHAIN, ADDR, INFLAG) - The combination of a bctrl
/// instruction and the TOC reload required on SVR4 PPC64.
BCTRL_LOAD_TOC,
/// Return with a flag operand, matched by 'blr'
RET_FLAG,
/// R32 = MFOCRF(CRREG, INFLAG) - Represents the MFOCRF instruction.
/// This copies the bits corresponding to the specified CRREG into the
/// resultant GPR. Bits corresponding to other CR regs are undefined.
MFOCRF,
/// Direct move from a VSX register to a GPR
MFVSR,
/// Direct move from a GPR to a VSX register (algebraic)
MTVSRA,
/// Direct move from a GPR to a VSX register (zero)
MTVSRZ,
Add CR-bit tracking to the PowerPC backend for i1 values This change enables tracking i1 values in the PowerPC backend using the condition register bits. These bits can be treated on PowerPC as separate registers; individual bit operations (and, or, xor, etc.) are supported. Tracking booleans in CR bits has several advantages: - Reduction in register pressure (because we no longer need GPRs to store boolean values). - Logical operations on booleans can be handled more efficiently; we used to have to move all results from comparisons into GPRs, perform promoted logical operations in GPRs, and then move the result back into condition register bits to be used by conditional branches. This can be very inefficient, because the throughput of these CR <-> GPR moves have high latency and low throughput (especially when other associated instructions are accounted for). - On the POWER7 and similar cores, we can increase total throughput by using the CR bits. CR bit operations have a dedicated functional unit. Most of this is more-or-less mechanical: Adjustments were needed in the calling-convention code, support was added for spilling/restoring individual condition-register bits, and conditional branch instruction definitions taking specific CR bits were added (plus patterns and code for generating bit-level operations). This is enabled by default when running at -O2 and higher. For -O0 and -O1, where the ability to debug is more important, this feature is disabled by default. Individual CR bits do not have assigned DWARF register numbers, and storing values in CR bits makes them invisible to the debugger. It is critical, however, that we don't move i1 values that have been promoted to larger values (such as those passed as function arguments) into bit registers only to quickly turn around and move the values back into GPRs (such as happens when values are returned by functions). A pair of target-specific DAG combines are added to remove the trunc/extends in: trunc(binary-ops(binary-ops(zext(x), zext(y)), ...) and: zext(binary-ops(binary-ops(trunc(x), trunc(y)), ...) In short, we only want to use CR bits where some of the i1 values come from comparisons or are used by conditional branches or selects. To put it another way, if we can do the entire i1 computation in GPRs, then we probably should (on the POWER7, the GPR-operation throughput is higher, and for all cores, the CR <-> GPR moves are expensive). POWER7 test-suite performance results (from 10 runs in each configuration): SingleSource/Benchmarks/Misc/mandel-2: 35% speedup MultiSource/Benchmarks/Prolangs-C++/city/city: 21% speedup MultiSource/Benchmarks/MiBench/automotive-susan: 23% speedup SingleSource/Benchmarks/CoyoteBench/huffbench: 13% speedup SingleSource/Benchmarks/Misc-C++/Large/sphereflake: 13% speedup SingleSource/Benchmarks/Misc-C++/mandel-text: 10% speedup SingleSource/Benchmarks/Misc-C++-EH/spirit: 10% slowdown MultiSource/Applications/lemon/lemon: 8% slowdown llvm-svn: 202451
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// FIXME: Remove these once the ANDI glue bug is fixed:
/// i1 = ANDIo_1_[EQ|GT]_BIT(i32 or i64 x) - Represents the result of the
/// eq or gt bit of CR0 after executing andi. x, 1. This is used to
/// implement truncation of i32 or i64 to i1.
ANDIo_1_EQ_BIT, ANDIo_1_GT_BIT,
// READ_TIME_BASE - A read of the 64-bit time-base register on a 32-bit
// target (returns (Lo, Hi)). It takes a chain operand.
READ_TIME_BASE,
// EH_SJLJ_SETJMP - SjLj exception handling setjmp.
EH_SJLJ_SETJMP,
// EH_SJLJ_LONGJMP - SjLj exception handling longjmp.
EH_SJLJ_LONGJMP,
/// RESVEC = VCMP(LHS, RHS, OPC) - Represents one of the altivec VCMP*
/// instructions. For lack of better number, we use the opcode number
/// encoding for the OPC field to identify the compare. For example, 838
/// is VCMPGTSH.
VCMP,
/// RESVEC, OUTFLAG = VCMPo(LHS, RHS, OPC) - Represents one of the
/// altivec VCMP*o instructions. For lack of better number, we use the
/// opcode number encoding for the OPC field to identify the compare. For
/// example, 838 is VCMPGTSH.
VCMPo,
/// CHAIN = COND_BRANCH CHAIN, CRRC, OPC, DESTBB [, INFLAG] - This
/// corresponds to the COND_BRANCH pseudo instruction. CRRC is the
/// condition register to branch on, OPC is the branch opcode to use (e.g.
/// PPC::BLE), DESTBB is the destination block to branch to, and INFLAG is
/// an optional input flag argument.
COND_BRANCH,
Implement PPC counter loops as a late IR-level pass The old PPCCTRLoops pass, like the Hexagon pass version from which it was derived, could only handle some simple loops in canonical form. We cannot directly adapt the new Hexagon hardware loops pass, however, because the Hexagon pass contains a fundamental assumption that non-constant-trip-count loops will contain a guard, and this is not always true (the result being that incorrect negative counts can be generated). With this commit, we replace the pass with a late IR-level pass which makes use of SE to calculate the backedge-taken counts and safely generate the loop-count expressions (including any necessary max() parts). This IR level pass inserts custom intrinsics that are lowered into the desired decrement-and-branch instructions. The most fragile part of this new implementation is that interfering uses of the counter register must be detected on the IR level (and, on PPC, this also includes any indirect branches in addition to function calls). Also, to make all of this work, we need a variant of the mtctr instruction that is marked as having side effects. Without this, machine-code level CSE, DCE, etc. illegally transform the resulting code. Hopefully, this can be improved in the future. This new pass is smaller than the original (and much smaller than the new Hexagon hardware loops pass), and can handle many additional cases correctly. In addition, the preheader-creation code has been copied from LoopSimplify, and after we decide on where it belongs, this code will be refactored so that it can be explicitly shared (making this implementation even smaller). The new test-case files ctrloop-{le,lt,ne}.ll have been adapted from tests for the new Hexagon pass. There are a few classes of loops that this pass does not transform (noted by FIXMEs in the files), but these deficiencies can be addressed within the SE infrastructure (thus helping many other passes as well). llvm-svn: 181927
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/// CHAIN = BDNZ CHAIN, DESTBB - These are used to create counter-based
/// loops.
BDNZ, BDZ,
/// F8RC = FADDRTZ F8RC, F8RC - This is an FADD done with rounding
/// towards zero. Used only as part of the long double-to-int
/// conversion sequence.
FADDRTZ,
/// F8RC = MFFS - This moves the FPSCR (not modeled) into the register.
MFFS,
/// TC_RETURN - A tail call return.
/// operand #0 chain
/// operand #1 callee (register or absolute)
/// operand #2 stack adjustment
/// operand #3 optional in flag
TC_RETURN,
/// ch, gl = CR6[UN]SET ch, inglue - Toggle CR bit 6 for SVR4 vararg calls
CR6SET,
CR6UNSET,
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/// GPRC = address of _GLOBAL_OFFSET_TABLE_. Used by initial-exec TLS
/// on PPC32.
PPC32_GOT,
/// GPRC = address of _GLOBAL_OFFSET_TABLE_. Used by general dynamic and
/// local dynamic TLS on PPC32.
PPC32_PICGOT,
/// G8RC = ADDIS_GOT_TPREL_HA %X2, Symbol - Used by the initial-exec
/// TLS model, produces an ADDIS8 instruction that adds the GOT
/// base to sym\@got\@tprel\@ha.
ADDIS_GOT_TPREL_HA,
/// G8RC = LD_GOT_TPREL_L Symbol, G8RReg - Used by the initial-exec
/// TLS model, produces a LD instruction with base register G8RReg
/// and offset sym\@got\@tprel\@l. This completes the addition that
/// finds the offset of "sym" relative to the thread pointer.
LD_GOT_TPREL_L,
/// G8RC = ADD_TLS G8RReg, Symbol - Used by the initial-exec TLS
/// model, produces an ADD instruction that adds the contents of
/// G8RReg to the thread pointer. Symbol contains a relocation
/// sym\@tls which is to be replaced by the thread pointer and
/// identifies to the linker that the instruction is part of a
/// TLS sequence.
ADD_TLS,
This patch implements the general dynamic TLS model for 64-bit PowerPC. Given a thread-local symbol x with global-dynamic access, the generated code to obtain x's address is: Instruction Relocation Symbol addis ra,r2,x@got@tlsgd@ha R_PPC64_GOT_TLSGD16_HA x addi r3,ra,x@got@tlsgd@l R_PPC64_GOT_TLSGD16_L x bl __tls_get_addr(x@tlsgd) R_PPC64_TLSGD x R_PPC64_REL24 __tls_get_addr nop <use address in r3> The implementation borrows from the medium code model work for introducing special forms of ADDIS and ADDI into the DAG representation. This is made slightly more complicated by having to introduce a call to the external function __tls_get_addr. Using the full call machinery is overkill and, more importantly, makes it difficult to add a special relocation. So I've introduced another opcode GET_TLS_ADDR to represent the function call, and surrounded it with register copies to set up the parameter and return value. Most of the code is pretty straightforward. I ran into one peculiarity when I introduced a new PPC opcode BL8_NOP_ELF_TLSGD, which is just like BL8_NOP_ELF except that it takes another parameter to represent the symbol ("x" above) that requires a relocation on the call. Something in the TblGen machinery causes BL8_NOP_ELF and BL8_NOP_ELF_TLSGD to be treated identically during the emit phase, so this second operand was never visited to generate relocations. This is the reason for the slightly messy workaround in PPCMCCodeEmitter.cpp:getDirectBrEncoding(). Two new tests are included to demonstrate correct external assembly and correct generation of relocations using the integrated assembler. Comments welcome! Thanks, Bill llvm-svn: 169910
2012-12-12 04:30:11 +08:00
/// G8RC = ADDIS_TLSGD_HA %X2, Symbol - For the general-dynamic TLS
/// model, produces an ADDIS8 instruction that adds the GOT base
/// register to sym\@got\@tlsgd\@ha.
This patch implements the general dynamic TLS model for 64-bit PowerPC. Given a thread-local symbol x with global-dynamic access, the generated code to obtain x's address is: Instruction Relocation Symbol addis ra,r2,x@got@tlsgd@ha R_PPC64_GOT_TLSGD16_HA x addi r3,ra,x@got@tlsgd@l R_PPC64_GOT_TLSGD16_L x bl __tls_get_addr(x@tlsgd) R_PPC64_TLSGD x R_PPC64_REL24 __tls_get_addr nop <use address in r3> The implementation borrows from the medium code model work for introducing special forms of ADDIS and ADDI into the DAG representation. This is made slightly more complicated by having to introduce a call to the external function __tls_get_addr. Using the full call machinery is overkill and, more importantly, makes it difficult to add a special relocation. So I've introduced another opcode GET_TLS_ADDR to represent the function call, and surrounded it with register copies to set up the parameter and return value. Most of the code is pretty straightforward. I ran into one peculiarity when I introduced a new PPC opcode BL8_NOP_ELF_TLSGD, which is just like BL8_NOP_ELF except that it takes another parameter to represent the symbol ("x" above) that requires a relocation on the call. Something in the TblGen machinery causes BL8_NOP_ELF and BL8_NOP_ELF_TLSGD to be treated identically during the emit phase, so this second operand was never visited to generate relocations. This is the reason for the slightly messy workaround in PPCMCCodeEmitter.cpp:getDirectBrEncoding(). Two new tests are included to demonstrate correct external assembly and correct generation of relocations using the integrated assembler. Comments welcome! Thanks, Bill llvm-svn: 169910
2012-12-12 04:30:11 +08:00
ADDIS_TLSGD_HA,
/// %X3 = ADDI_TLSGD_L G8RReg, Symbol - For the general-dynamic TLS
This patch implements the general dynamic TLS model for 64-bit PowerPC. Given a thread-local symbol x with global-dynamic access, the generated code to obtain x's address is: Instruction Relocation Symbol addis ra,r2,x@got@tlsgd@ha R_PPC64_GOT_TLSGD16_HA x addi r3,ra,x@got@tlsgd@l R_PPC64_GOT_TLSGD16_L x bl __tls_get_addr(x@tlsgd) R_PPC64_TLSGD x R_PPC64_REL24 __tls_get_addr nop <use address in r3> The implementation borrows from the medium code model work for introducing special forms of ADDIS and ADDI into the DAG representation. This is made slightly more complicated by having to introduce a call to the external function __tls_get_addr. Using the full call machinery is overkill and, more importantly, makes it difficult to add a special relocation. So I've introduced another opcode GET_TLS_ADDR to represent the function call, and surrounded it with register copies to set up the parameter and return value. Most of the code is pretty straightforward. I ran into one peculiarity when I introduced a new PPC opcode BL8_NOP_ELF_TLSGD, which is just like BL8_NOP_ELF except that it takes another parameter to represent the symbol ("x" above) that requires a relocation on the call. Something in the TblGen machinery causes BL8_NOP_ELF and BL8_NOP_ELF_TLSGD to be treated identically during the emit phase, so this second operand was never visited to generate relocations. This is the reason for the slightly messy workaround in PPCMCCodeEmitter.cpp:getDirectBrEncoding(). Two new tests are included to demonstrate correct external assembly and correct generation of relocations using the integrated assembler. Comments welcome! Thanks, Bill llvm-svn: 169910
2012-12-12 04:30:11 +08:00
/// model, produces an ADDI8 instruction that adds G8RReg to
/// sym\@got\@tlsgd\@l and stores the result in X3. Hidden by
/// ADDIS_TLSGD_L_ADDR until after register assignment.
This patch implements the general dynamic TLS model for 64-bit PowerPC. Given a thread-local symbol x with global-dynamic access, the generated code to obtain x's address is: Instruction Relocation Symbol addis ra,r2,x@got@tlsgd@ha R_PPC64_GOT_TLSGD16_HA x addi r3,ra,x@got@tlsgd@l R_PPC64_GOT_TLSGD16_L x bl __tls_get_addr(x@tlsgd) R_PPC64_TLSGD x R_PPC64_REL24 __tls_get_addr nop <use address in r3> The implementation borrows from the medium code model work for introducing special forms of ADDIS and ADDI into the DAG representation. This is made slightly more complicated by having to introduce a call to the external function __tls_get_addr. Using the full call machinery is overkill and, more importantly, makes it difficult to add a special relocation. So I've introduced another opcode GET_TLS_ADDR to represent the function call, and surrounded it with register copies to set up the parameter and return value. Most of the code is pretty straightforward. I ran into one peculiarity when I introduced a new PPC opcode BL8_NOP_ELF_TLSGD, which is just like BL8_NOP_ELF except that it takes another parameter to represent the symbol ("x" above) that requires a relocation on the call. Something in the TblGen machinery causes BL8_NOP_ELF and BL8_NOP_ELF_TLSGD to be treated identically during the emit phase, so this second operand was never visited to generate relocations. This is the reason for the slightly messy workaround in PPCMCCodeEmitter.cpp:getDirectBrEncoding(). Two new tests are included to demonstrate correct external assembly and correct generation of relocations using the integrated assembler. Comments welcome! Thanks, Bill llvm-svn: 169910
2012-12-12 04:30:11 +08:00
ADDI_TLSGD_L,
/// %X3 = GET_TLS_ADDR %X3, Symbol - For the general-dynamic TLS
/// model, produces a call to __tls_get_addr(sym\@tlsgd). Hidden by
/// ADDIS_TLSGD_L_ADDR until after register assignment.
GET_TLS_ADDR,
/// G8RC = ADDI_TLSGD_L_ADDR G8RReg, Symbol, Symbol - Op that
/// combines ADDI_TLSGD_L and GET_TLS_ADDR until expansion following
/// register assignment.
ADDI_TLSGD_L_ADDR,
/// G8RC = ADDIS_TLSLD_HA %X2, Symbol - For the local-dynamic TLS
/// model, produces an ADDIS8 instruction that adds the GOT base
/// register to sym\@got\@tlsld\@ha.
ADDIS_TLSLD_HA,
/// %X3 = ADDI_TLSLD_L G8RReg, Symbol - For the local-dynamic TLS
/// model, produces an ADDI8 instruction that adds G8RReg to
/// sym\@got\@tlsld\@l and stores the result in X3. Hidden by
/// ADDIS_TLSLD_L_ADDR until after register assignment.
ADDI_TLSLD_L,
/// %X3 = GET_TLSLD_ADDR %X3, Symbol - For the local-dynamic TLS
/// model, produces a call to __tls_get_addr(sym\@tlsld). Hidden by
/// ADDIS_TLSLD_L_ADDR until after register assignment.
GET_TLSLD_ADDR,
/// G8RC = ADDI_TLSLD_L_ADDR G8RReg, Symbol, Symbol - Op that
/// combines ADDI_TLSLD_L and GET_TLSLD_ADDR until expansion
/// following register assignment.
ADDI_TLSLD_L_ADDR,
/// G8RC = ADDIS_DTPREL_HA %X3, Symbol - For the local-dynamic TLS
/// model, produces an ADDIS8 instruction that adds X3 to
/// sym\@dtprel\@ha.
ADDIS_DTPREL_HA,
/// G8RC = ADDI_DTPREL_L G8RReg, Symbol - For the local-dynamic TLS
/// model, produces an ADDI8 instruction that adds G8RReg to
/// sym\@got\@dtprel\@l.
ADDI_DTPREL_L,
/// VRRC = VADD_SPLAT Elt, EltSize - Temporary node to be expanded
/// during instruction selection to optimize a BUILD_VECTOR into
/// operations on splats. This is necessary to avoid losing these
/// optimizations due to constant folding.
VADD_SPLAT,
/// CHAIN = SC CHAIN, Imm128 - System call. The 7-bit unsigned
/// operand identifies the operating system entry point.
SC,
/// CHAIN = CLRBHRB CHAIN - Clear branch history rolling buffer.
CLRBHRB,
/// GPRC, CHAIN = MFBHRBE CHAIN, Entry, Dummy - Move from branch
/// history rolling buffer entry.
MFBHRBE,
/// CHAIN = RFEBB CHAIN, State - Return from event-based branch.
RFEBB,
[PowerPC 1/4] Little-endian adjustments for VSX loads/stores This patch addresses the inherent big-endian bias in the lxvd2x, lxvw4x, stxvd2x, and stxvw4x instructions. These instructions load vector elements into registers left-to-right (with the first element loaded into the high-order bits of the register), regardless of the endian setting of the processor. However, these are the only vector memory instructions that permit unaligned storage accesses, so we want to use them for little-endian. To make this work, a lxvd2x or lxvw4x is replaced with an lxvd2x followed by an xxswapd, which swaps the doublewords. This works for lxvw4x as well as lxvd2x, because for lxvw4x on an LE system the vector elements are in LE order (right-to-left) within each doubleword. (Thus after lxvw2x of a <4 x float> the elements will appear as 1, 0, 3, 2. Following the swap, they will appear as 3, 2, 0, 1, as desired.) For stores, an stxvd2x or stxvw4x is replaced with an stxvd2x preceded by an xxswapd. Introduction of extra swap instructions provides correctness, but obviously is not ideal from a performance perspective. Future patches will address this with optimizations to remove most of the introduced swaps, which have proven effective in other implementations. The introduction of the swaps is performed during lowering of LOAD, STORE, INTRINSIC_W_CHAIN, and INTRINSIC_VOID operations. The latter are used to translate intrinsics that specify the VSX loads and stores directly into equivalent sequences for little endian. Thus code that uses vec_vsx_ld and vec_vsx_st does not have to be modified to be ported from BE to LE. We introduce new PPCISD opcodes for LXVD2X, STXVD2X, and XXSWAPD for use during this lowering step. In PPCInstrVSX.td, we add new SDType and SDNode definitions for these (PPClxvd2x, PPCstxvd2x, PPCxxswapd). These are recognized during instruction selection and mapped to the correct instructions. Several tests that were written to use -mcpu=pwr7 or pwr8 are modified to disable VSX on LE variants because code generation changes with this and subsequent patches in this set. I chose to include all of these in the first patch than try to rigorously sort out which tests were broken by one or another of the patches. Sorry about that. The new test vsx-ldst-builtin-le.ll, and the changes to vsx-ldst.ll, are disabled until LE support is enabled because of breakages that occur as noted in those tests. They are re-enabled in patch 4/4. llvm-svn: 223783
2014-12-10 00:35:51 +08:00
/// VSRC, CHAIN = XXSWAPD CHAIN, VSRC - Occurs only for little
/// endian. Maps to an xxswapd instruction that corrects an lxvd2x
/// or stxvd2x instruction. The chain is necessary because the
/// sequence replaces a load and needs to provide the same number
/// of outputs.
XXSWAPD,
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/// QVFPERM = This corresponds to the QPX qvfperm instruction.
QVFPERM,
/// QVGPCI = This corresponds to the QPX qvgpci instruction.
QVGPCI,
/// QVALIGNI = This corresponds to the QPX qvaligni instruction.
QVALIGNI,
/// QVESPLATI = This corresponds to the QPX qvesplati instruction.
QVESPLATI,
/// QBFLT = Access the underlying QPX floating-point boolean
/// representation.
QBFLT,
/// CHAIN = STBRX CHAIN, GPRC, Ptr, Type - This is a
/// byte-swapping store instruction. It byte-swaps the low "Type" bits of
/// the GPRC input, then stores it through Ptr. Type can be either i16 or
/// i32.
STBRX = ISD::FIRST_TARGET_MEMORY_OPCODE,
/// GPRC, CHAIN = LBRX CHAIN, Ptr, Type - This is a
/// byte-swapping load instruction. It loads "Type" bits, byte swaps it,
/// then puts it in the bottom bits of the GPRC. TYPE can be either i16
/// or i32.
This patch implements medium code model support for 64-bit PowerPC. The default for 64-bit PowerPC is small code model, in which TOC entries must be addressable using a 16-bit offset from the TOC pointer. Additionally, only TOC entries are addressed via the TOC pointer. With medium code model, TOC entries and data sections can all be addressed via the TOC pointer using a 32-bit offset. Cooperation with the linker allows 16-bit offsets to be used when these are sufficient, reducing the number of extra instructions that need to be executed. Medium code model also does not generate explicit TOC entries in ".section toc" for variables that are wholly internal to the compilation unit. Consider a load of an external 4-byte integer. With small code model, the compiler generates: ld 3, .LC1@toc(2) lwz 4, 0(3) .section .toc,"aw",@progbits .LC1: .tc ei[TC],ei With medium model, it instead generates: addis 3, 2, .LC1@toc@ha ld 3, .LC1@toc@l(3) lwz 4, 0(3) .section .toc,"aw",@progbits .LC1: .tc ei[TC],ei Here .LC1@toc@ha is a relocation requesting the upper 16 bits of the 32-bit offset of ei's TOC entry from the TOC base pointer. Similarly, .LC1@toc@l is a relocation requesting the lower 16 bits. Note that if the linker determines that ei's TOC entry is within a 16-bit offset of the TOC base pointer, it will replace the "addis" with a "nop", and replace the "ld" with the identical "ld" instruction from the small code model example. Consider next a load of a function-scope static integer. For small code model, the compiler generates: ld 3, .LC1@toc(2) lwz 4, 0(3) .section .toc,"aw",@progbits .LC1: .tc test_fn_static.si[TC],test_fn_static.si .type test_fn_static.si,@object .local test_fn_static.si .comm test_fn_static.si,4,4 For medium code model, the compiler generates: addis 3, 2, test_fn_static.si@toc@ha addi 3, 3, test_fn_static.si@toc@l lwz 4, 0(3) .type test_fn_static.si,@object .local test_fn_static.si .comm test_fn_static.si,4,4 Again, the linker may replace the "addis" with a "nop", calculating only a 16-bit offset when this is sufficient. Note that it would be more efficient for the compiler to generate: addis 3, 2, test_fn_static.si@toc@ha lwz 4, test_fn_static.si@toc@l(3) The current patch does not perform this optimization yet. This will be addressed as a peephole optimization in a later patch. For the moment, the default code model for 64-bit PowerPC will remain the small code model. We plan to eventually change the default to medium code model, which matches current upstream GCC behavior. Note that the different code models are ABI-compatible, so code compiled with different models will be linked and execute correctly. I've tested the regression suite and the application/benchmark test suite in two ways: Once with the patch as submitted here, and once with additional logic to force medium code model as the default. The tests all compile cleanly, with one exception. The mandel-2 application test fails due to an unrelated ABI compatibility with passing complex numbers. It just so happens that small code model was incredibly lucky, in that temporary values in floating-point registers held the expected values needed by the external library routine that was called incorrectly. My current thought is to correct the ABI problems with _Complex before making medium code model the default, to avoid introducing this "regression." Here are a few comments on how the patch works, since the selection code can be difficult to follow: The existing logic for small code model defines three pseudo-instructions: LDtoc for most uses, LDtocJTI for jump table addresses, and LDtocCPT for constant pool addresses. These are expanded by SelectCodeCommon(). The pseudo-instruction approach doesn't work for medium code model, because we need to generate two instructions when we match the same pattern. Instead, new logic in PPCDAGToDAGISel::Select() intercepts the TOC_ENTRY node for medium code model, and generates an ADDIStocHA followed by either a LDtocL or an ADDItocL. These new node types correspond naturally to the sequences described above. The addis/ld sequence is generated for the following cases: * Jump table addresses * Function addresses * External global variables * Tentative definitions of global variables (common linkage) The addis/addi sequence is generated for the following cases: * Constant pool entries * File-scope static global variables * Function-scope static variables Expanding to the two-instruction sequences at select time exposes the instructions to subsequent optimization, particularly scheduling. The rest of the processing occurs at assembly time, in PPCAsmPrinter::EmitInstruction. Each of the instructions is converted to a "real" PowerPC instruction. When a TOC entry needs to be created, this is done here in the same manner as for the existing LDtoc, LDtocJTI, and LDtocCPT pseudo-instructions (I factored out a new routine to handle this). I had originally thought that if a TOC entry was needed for LDtocL or ADDItocL, it would already have been generated for the previous ADDIStocHA. However, at higher optimization levels, the ADDIStocHA may appear in a different block, which may be assembled textually following the block containing the LDtocL or ADDItocL. So it is necessary to include the possibility of creating a new TOC entry for those two instructions. Note that for LDtocL, we generate a new form of LD called LDrs. This allows specifying the @toc@l relocation for the offset field of the LD instruction (i.e., the offset is replaced by a SymbolLo relocation). When the peephole optimization described above is added, we will need to do similar things for all immediate-form load and store operations. The seven "mcm-n.ll" test cases are kept separate because otherwise the intermingling of various TOC entries and so forth makes the tests fragile and hard to understand. The above assumes use of an external assembler. For use of the integrated assembler, new relocations are added and used by PPCELFObjectWriter. Testing is done with "mcm-obj.ll", which tests for proper generation of the various relocations for the same sequences tested with the external assembler. llvm-svn: 168708
2012-11-28 01:35:46 +08:00
LBRX,
/// STFIWX - The STFIWX instruction. The first operand is an input token
/// chain, then an f64 value to store, then an address to store it to.
STFIWX,
/// GPRC, CHAIN = LFIWAX CHAIN, Ptr - This is a floating-point
/// load which sign-extends from a 32-bit integer value into the
/// destination 64-bit register.
LFIWAX,
/// GPRC, CHAIN = LFIWZX CHAIN, Ptr - This is a floating-point
/// load which zero-extends from a 32-bit integer value into the
/// destination 64-bit register.
LFIWZX,
[PowerPC 1/4] Little-endian adjustments for VSX loads/stores This patch addresses the inherent big-endian bias in the lxvd2x, lxvw4x, stxvd2x, and stxvw4x instructions. These instructions load vector elements into registers left-to-right (with the first element loaded into the high-order bits of the register), regardless of the endian setting of the processor. However, these are the only vector memory instructions that permit unaligned storage accesses, so we want to use them for little-endian. To make this work, a lxvd2x or lxvw4x is replaced with an lxvd2x followed by an xxswapd, which swaps the doublewords. This works for lxvw4x as well as lxvd2x, because for lxvw4x on an LE system the vector elements are in LE order (right-to-left) within each doubleword. (Thus after lxvw2x of a <4 x float> the elements will appear as 1, 0, 3, 2. Following the swap, they will appear as 3, 2, 0, 1, as desired.) For stores, an stxvd2x or stxvw4x is replaced with an stxvd2x preceded by an xxswapd. Introduction of extra swap instructions provides correctness, but obviously is not ideal from a performance perspective. Future patches will address this with optimizations to remove most of the introduced swaps, which have proven effective in other implementations. The introduction of the swaps is performed during lowering of LOAD, STORE, INTRINSIC_W_CHAIN, and INTRINSIC_VOID operations. The latter are used to translate intrinsics that specify the VSX loads and stores directly into equivalent sequences for little endian. Thus code that uses vec_vsx_ld and vec_vsx_st does not have to be modified to be ported from BE to LE. We introduce new PPCISD opcodes for LXVD2X, STXVD2X, and XXSWAPD for use during this lowering step. In PPCInstrVSX.td, we add new SDType and SDNode definitions for these (PPClxvd2x, PPCstxvd2x, PPCxxswapd). These are recognized during instruction selection and mapped to the correct instructions. Several tests that were written to use -mcpu=pwr7 or pwr8 are modified to disable VSX on LE variants because code generation changes with this and subsequent patches in this set. I chose to include all of these in the first patch than try to rigorously sort out which tests were broken by one or another of the patches. Sorry about that. The new test vsx-ldst-builtin-le.ll, and the changes to vsx-ldst.ll, are disabled until LE support is enabled because of breakages that occur as noted in those tests. They are re-enabled in patch 4/4. llvm-svn: 223783
2014-12-10 00:35:51 +08:00
/// VSRC, CHAIN = LXVD2X_LE CHAIN, Ptr - Occurs only for little endian.
/// Maps directly to an lxvd2x instruction that will be followed by
/// an xxswapd.
LXVD2X,
/// CHAIN = STXVD2X CHAIN, VSRC, Ptr - Occurs only for little endian.
/// Maps directly to an stxvd2x instruction that will be preceded by
/// an xxswapd.
2015-02-25 09:06:45 +08:00
STXVD2X,
/// QBRC, CHAIN = QVLFSb CHAIN, Ptr
/// The 4xf32 load used for v4i1 constants.
QVLFSb,
/// GPRC = TOC_ENTRY GA, TOC
/// Loads the entry for GA from the TOC, where the TOC base is given by
/// the last operand.
TOC_ENTRY
};
}
/// Define some predicates that are used for node matching.
namespace PPC {
/// isVPKUHUMShuffleMask - Return true if this is the shuffle mask for a
/// VPKUHUM instruction.
bool isVPKUHUMShuffleMask(ShuffleVectorSDNode *N, unsigned ShuffleKind,
SelectionDAG &DAG);
/// isVPKUWUMShuffleMask - Return true if this is the shuffle mask for a
/// VPKUWUM instruction.
bool isVPKUWUMShuffleMask(ShuffleVectorSDNode *N, unsigned ShuffleKind,
SelectionDAG &DAG);
/// isVPKUDUMShuffleMask - Return true if this is the shuffle mask for a
/// VPKUDUM instruction.
bool isVPKUDUMShuffleMask(ShuffleVectorSDNode *N, unsigned ShuffleKind,
SelectionDAG &DAG);
/// isVMRGLShuffleMask - Return true if this is a shuffle mask suitable for
/// a VRGL* instruction with the specified unit size (1,2 or 4 bytes).
bool isVMRGLShuffleMask(ShuffleVectorSDNode *N, unsigned UnitSize,
unsigned ShuffleKind, SelectionDAG &DAG);
/// isVMRGHShuffleMask - Return true if this is a shuffle mask suitable for
/// a VRGH* instruction with the specified unit size (1,2 or 4 bytes).
bool isVMRGHShuffleMask(ShuffleVectorSDNode *N, unsigned UnitSize,
unsigned ShuffleKind, SelectionDAG &DAG);
/// isVMRGEOShuffleMask - Return true if this is a shuffle mask suitable for
/// a VMRGEW or VMRGOW instruction
bool isVMRGEOShuffleMask(ShuffleVectorSDNode *N, bool CheckEven,
unsigned ShuffleKind, SelectionDAG &DAG);
/// isVSLDOIShuffleMask - If this is a vsldoi shuffle mask, return the
/// shift amount, otherwise return -1.
int isVSLDOIShuffleMask(SDNode *N, unsigned ShuffleKind,
SelectionDAG &DAG);
/// isSplatShuffleMask - Return true if the specified VECTOR_SHUFFLE operand
/// specifies a splat of a single element that is suitable for input to
/// VSPLTB/VSPLTH/VSPLTW.
bool isSplatShuffleMask(ShuffleVectorSDNode *N, unsigned EltSize);
/// getVSPLTImmediate - Return the appropriate VSPLT* immediate to splat the
/// specified isSplatShuffleMask VECTOR_SHUFFLE mask.
unsigned getVSPLTImmediate(SDNode *N, unsigned EltSize, SelectionDAG &DAG);
/// get_VSPLTI_elt - If this is a build_vector of constants which can be
/// formed by using a vspltis[bhw] instruction of the specified element
/// size, return the constant being splatted. The ByteSize field indicates
/// the number of bytes of each element [124] -> [bhw].
SDValue get_VSPLTI_elt(SDNode *N, unsigned ByteSize, SelectionDAG &DAG);
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/// If this is a qvaligni shuffle mask, return the shift
/// amount, otherwise return -1.
int isQVALIGNIShuffleMask(SDNode *N);
}
class PPCTargetLowering : public TargetLowering {
const PPCSubtarget &Subtarget;
public:
explicit PPCTargetLowering(const PPCTargetMachine &TM,
const PPCSubtarget &STI);
/// getTargetNodeName() - This method returns the name of a target specific
/// DAG node.
const char *getTargetNodeName(unsigned Opcode) const override;
MVT getScalarShiftAmountTy(const DataLayout &) const override {
return MVT::i32;
}
bool isCheapToSpeculateCttz() const override {
return true;
}
bool isCheapToSpeculateCtlz() const override {
return true;
}
/// getSetCCResultType - Return the ISD::SETCC ValueType
EVT getSetCCResultType(const DataLayout &DL, LLVMContext &Context,
EVT VT) const override;
/// Return true if target always beneficiates from combining into FMA for a
/// given value type. This must typically return false on targets where FMA
/// takes more cycles to execute than FADD.
bool enableAggressiveFMAFusion(EVT VT) const override;
/// getPreIndexedAddressParts - returns true by value, base pointer and
/// offset pointer and addressing mode by reference if the node's address
/// can be legally represented as pre-indexed load / store address.
bool getPreIndexedAddressParts(SDNode *N, SDValue &Base,
SDValue &Offset,
ISD::MemIndexedMode &AM,
SelectionDAG &DAG) const override;
/// SelectAddressRegReg - Given the specified addressed, check to see if it
/// can be represented as an indexed [r+r] operation. Returns false if it
/// can be more efficiently represented with [r+imm].
bool SelectAddressRegReg(SDValue N, SDValue &Base, SDValue &Index,
SelectionDAG &DAG) const;
/// SelectAddressRegImm - Returns true if the address N can be represented
/// by a base register plus a signed 16-bit displacement [r+imm], and if it
[PowerPC] Use true offset value in "memrix" machine operands This is the second part of the change to always return "true" offset values from getPreIndexedAddressParts, tackling the case of "memrix" type operands. This is about instructions like LD/STD that only have a 14-bit field to encode immediate offsets, which are implicitly extended by two zero bits by the machine, so that in effect we can access 16-bit offsets as long as they are a multiple of 4. The PowerPC back end currently handles such instructions by carrying the 14-bit value (as it will get encoded into the actual machine instructions) in the machine operand fields for such instructions. This means that those values are in fact not the true offset, but rather the offset divided by 4 (and then truncated to an unsigned 14-bit value). Like in the case fixed in r182012, this makes common code operations on such offset values not work as expected. Furthermore, there doesn't really appear to be any strong reason why we should encode machine operands this way. This patch therefore changes the encoding of "memrix" type machine operands to simply contain the "true" offset value as a signed immediate value, while enforcing the rules that it must fit in a 16-bit signed value and must also be a multiple of 4. This change must be made simultaneously in all places that access machine operands of this type. However, just about all those changes make the code simpler; in many cases we can now just share the same code for memri and memrix operands. llvm-svn: 182032
2013-05-17 01:58:02 +08:00
/// is not better represented as reg+reg. If Aligned is true, only accept
/// displacements suitable for STD and friends, i.e. multiples of 4.
bool SelectAddressRegImm(SDValue N, SDValue &Disp, SDValue &Base,
[PowerPC] Use true offset value in "memrix" machine operands This is the second part of the change to always return "true" offset values from getPreIndexedAddressParts, tackling the case of "memrix" type operands. This is about instructions like LD/STD that only have a 14-bit field to encode immediate offsets, which are implicitly extended by two zero bits by the machine, so that in effect we can access 16-bit offsets as long as they are a multiple of 4. The PowerPC back end currently handles such instructions by carrying the 14-bit value (as it will get encoded into the actual machine instructions) in the machine operand fields for such instructions. This means that those values are in fact not the true offset, but rather the offset divided by 4 (and then truncated to an unsigned 14-bit value). Like in the case fixed in r182012, this makes common code operations on such offset values not work as expected. Furthermore, there doesn't really appear to be any strong reason why we should encode machine operands this way. This patch therefore changes the encoding of "memrix" type machine operands to simply contain the "true" offset value as a signed immediate value, while enforcing the rules that it must fit in a 16-bit signed value and must also be a multiple of 4. This change must be made simultaneously in all places that access machine operands of this type. However, just about all those changes make the code simpler; in many cases we can now just share the same code for memri and memrix operands. llvm-svn: 182032
2013-05-17 01:58:02 +08:00
SelectionDAG &DAG, bool Aligned) const;
/// SelectAddressRegRegOnly - Given the specified addressed, force it to be
/// represented as an indexed [r+r] operation.
bool SelectAddressRegRegOnly(SDValue N, SDValue &Base, SDValue &Index,
SelectionDAG &DAG) const;
Sched::Preference getSchedulingPreference(SDNode *N) const override;
/// LowerOperation - Provide custom lowering hooks for some operations.
///
SDValue LowerOperation(SDValue Op, SelectionDAG &DAG) const override;
/// ReplaceNodeResults - Replace the results of node with an illegal result
/// type with new values built out of custom code.
///
void ReplaceNodeResults(SDNode *N, SmallVectorImpl<SDValue>&Results,
SelectionDAG &DAG) const override;
[PowerPC 1/4] Little-endian adjustments for VSX loads/stores This patch addresses the inherent big-endian bias in the lxvd2x, lxvw4x, stxvd2x, and stxvw4x instructions. These instructions load vector elements into registers left-to-right (with the first element loaded into the high-order bits of the register), regardless of the endian setting of the processor. However, these are the only vector memory instructions that permit unaligned storage accesses, so we want to use them for little-endian. To make this work, a lxvd2x or lxvw4x is replaced with an lxvd2x followed by an xxswapd, which swaps the doublewords. This works for lxvw4x as well as lxvd2x, because for lxvw4x on an LE system the vector elements are in LE order (right-to-left) within each doubleword. (Thus after lxvw2x of a <4 x float> the elements will appear as 1, 0, 3, 2. Following the swap, they will appear as 3, 2, 0, 1, as desired.) For stores, an stxvd2x or stxvw4x is replaced with an stxvd2x preceded by an xxswapd. Introduction of extra swap instructions provides correctness, but obviously is not ideal from a performance perspective. Future patches will address this with optimizations to remove most of the introduced swaps, which have proven effective in other implementations. The introduction of the swaps is performed during lowering of LOAD, STORE, INTRINSIC_W_CHAIN, and INTRINSIC_VOID operations. The latter are used to translate intrinsics that specify the VSX loads and stores directly into equivalent sequences for little endian. Thus code that uses vec_vsx_ld and vec_vsx_st does not have to be modified to be ported from BE to LE. We introduce new PPCISD opcodes for LXVD2X, STXVD2X, and XXSWAPD for use during this lowering step. In PPCInstrVSX.td, we add new SDType and SDNode definitions for these (PPClxvd2x, PPCstxvd2x, PPCxxswapd). These are recognized during instruction selection and mapped to the correct instructions. Several tests that were written to use -mcpu=pwr7 or pwr8 are modified to disable VSX on LE variants because code generation changes with this and subsequent patches in this set. I chose to include all of these in the first patch than try to rigorously sort out which tests were broken by one or another of the patches. Sorry about that. The new test vsx-ldst-builtin-le.ll, and the changes to vsx-ldst.ll, are disabled until LE support is enabled because of breakages that occur as noted in those tests. They are re-enabled in patch 4/4. llvm-svn: 223783
2014-12-10 00:35:51 +08:00
SDValue expandVSXLoadForLE(SDNode *N, DAGCombinerInfo &DCI) const;
SDValue expandVSXStoreForLE(SDNode *N, DAGCombinerInfo &DCI) const;
SDValue PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI) const override;
SDValue BuildSDIVPow2(SDNode *N, const APInt &Divisor, SelectionDAG &DAG,
std::vector<SDNode *> *Created) const override;
unsigned getRegisterByName(const char* RegName, EVT VT) const override;
void computeKnownBitsForTargetNode(const SDValue Op,
APInt &KnownZero,
APInt &KnownOne,
const SelectionDAG &DAG,
unsigned Depth = 0) const override;
unsigned getPrefLoopAlignment(MachineLoop *ML) const override;
Instruction* emitLeadingFence(IRBuilder<> &Builder, AtomicOrdering Ord,
bool IsStore, bool IsLoad) const override;
Instruction* emitTrailingFence(IRBuilder<> &Builder, AtomicOrdering Ord,
bool IsStore, bool IsLoad) const override;
MachineBasicBlock *
EmitInstrWithCustomInserter(MachineInstr *MI,
MachineBasicBlock *MBB) const override;
MachineBasicBlock *EmitAtomicBinary(MachineInstr *MI,
MachineBasicBlock *MBB,
unsigned AtomicSize,
unsigned BinOpcode) const;
MachineBasicBlock *EmitPartwordAtomicBinary(MachineInstr *MI,
MachineBasicBlock *MBB,
bool is8bit, unsigned Opcode) const;
MachineBasicBlock *emitEHSjLjSetJmp(MachineInstr *MI,
MachineBasicBlock *MBB) const;
MachineBasicBlock *emitEHSjLjLongJmp(MachineInstr *MI,
MachineBasicBlock *MBB) const;
ConstraintType getConstraintType(StringRef Constraint) const override;
/// Examine constraint string and operand type and determine a weight value.
/// The operand object must already have been set up with the operand type.
ConstraintWeight getSingleConstraintMatchWeight(
AsmOperandInfo &info, const char *constraint) const override;
std::pair<unsigned, const TargetRegisterClass *>
getRegForInlineAsmConstraint(const TargetRegisterInfo *TRI,
StringRef Constraint, MVT VT) const override;
/// getByValTypeAlignment - Return the desired alignment for ByVal aggregate
/// function arguments in the caller parameter area. This is the actual
/// alignment, not its logarithm.
unsigned getByValTypeAlignment(Type *Ty,
const DataLayout &DL) const override;
/// LowerAsmOperandForConstraint - Lower the specified operand into the Ops
/// vector. If it is invalid, don't add anything to Ops.
void LowerAsmOperandForConstraint(SDValue Op,
std::string &Constraint,
std::vector<SDValue> &Ops,
SelectionDAG &DAG) const override;
unsigned
getInlineAsmMemConstraint(StringRef ConstraintCode) const override {
if (ConstraintCode == "es")
return InlineAsm::Constraint_es;
else if (ConstraintCode == "o")
return InlineAsm::Constraint_o;
else if (ConstraintCode == "Q")
return InlineAsm::Constraint_Q;
else if (ConstraintCode == "Z")
return InlineAsm::Constraint_Z;
else if (ConstraintCode == "Zy")
return InlineAsm::Constraint_Zy;
return TargetLowering::getInlineAsmMemConstraint(ConstraintCode);
}
/// isLegalAddressingMode - Return true if the addressing mode represented
/// by AM is legal for this target, for a load/store of the specified type.
bool isLegalAddressingMode(const AddrMode &AM, Type *Ty,
unsigned AS) const override;
/// isLegalICmpImmediate - Return true if the specified immediate is legal
/// icmp immediate, that is the target has icmp instructions which can
/// compare a register against the immediate without having to materialize
/// the immediate into a register.
bool isLegalICmpImmediate(int64_t Imm) const override;
/// isLegalAddImmediate - Return true if the specified immediate is legal
/// add immediate, that is the target has add instructions which can
/// add a register and the immediate without having to materialize
/// the immediate into a register.
bool isLegalAddImmediate(int64_t Imm) const override;
/// isTruncateFree - Return true if it's free to truncate a value of
/// type Ty1 to type Ty2. e.g. On PPC it's free to truncate a i64 value in
/// register X1 to i32 by referencing its sub-register R1.
bool isTruncateFree(Type *Ty1, Type *Ty2) const override;
bool isTruncateFree(EVT VT1, EVT VT2) const override;
bool isZExtFree(SDValue Val, EVT VT2) const override;
bool isFPExtFree(EVT VT) const override;
/// \brief Returns true if it is beneficial to convert a load of a constant
/// to just the constant itself.
bool shouldConvertConstantLoadToIntImm(const APInt &Imm,
Type *Ty) const override;
bool isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const override;
bool getTgtMemIntrinsic(IntrinsicInfo &Info,
const CallInst &I,
unsigned Intrinsic) const override;
/// getOptimalMemOpType - Returns the target specific optimal type for load
/// and store operations as a result of memset, memcpy, and memmove
/// lowering. If DstAlign is zero that means it's safe to destination
/// alignment can satisfy any constraint. Similarly if SrcAlign is zero it
/// means there isn't a need to check it against alignment requirement,
/// probably because the source does not need to be loaded. If 'IsMemset' is
/// true, that means it's expanding a memset. If 'ZeroMemset' is true, that
/// means it's a memset of zero. 'MemcpyStrSrc' indicates whether the memcpy
/// source is constant so it does not need to be loaded.
/// It returns EVT::Other if the type should be determined using generic
/// target-independent logic.
EVT
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getOptimalMemOpType(uint64_t Size, unsigned DstAlign, unsigned SrcAlign,
bool IsMemset, bool ZeroMemset, bool MemcpyStrSrc,
MachineFunction &MF) const override;
/// Is unaligned memory access allowed for the given type, and is it fast
/// relative to software emulation.
bool allowsMisalignedMemoryAccesses(EVT VT,
unsigned AddrSpace,
unsigned Align = 1,
bool *Fast = nullptr) const override;
/// isFMAFasterThanFMulAndFAdd - Return true if an FMA operation is faster
/// than a pair of fmul and fadd instructions. fmuladd intrinsics will be
/// expanded to FMAs when this method returns true, otherwise fmuladd is
/// expanded to fmul + fadd.
bool isFMAFasterThanFMulAndFAdd(EVT VT) const override;
const MCPhysReg *getScratchRegisters(CallingConv::ID CC) const override;
// Should we expand the build vector with shuffles?
bool
shouldExpandBuildVectorWithShuffles(EVT VT,
unsigned DefinedValues) const override;
/// createFastISel - This method returns a target-specific FastISel object,
/// or null if the target does not support "fast" instruction selection.
FastISel *createFastISel(FunctionLoweringInfo &FuncInfo,
const TargetLibraryInfo *LibInfo) const override;
[PowerPC] ELFv2 aggregate passing support This patch adds infrastructure support for passing array types directly. These can be used by the front-end to pass aggregate types (coerced to an appropriate array type). The details of the array type being used inform the back-end about ABI-relevant properties. Specifically, the array element type encodes: - whether the parameter should be passed in FPRs, VRs, or just GPRs/stack slots (for float / vector / integer element types, respectively) - what the alignment requirements of the parameter are when passed in GPRs/stack slots (8 for float / 16 for vector / the element type size for integer element types) -- this corresponds to the "byval align" field Using the infrastructure provided by this patch, a companion patch to clang will enable two features: - In the ELFv2 ABI, pass (and return) "homogeneous" floating-point or vector aggregates in FPRs and VRs (this is similar to the ARM homogeneous aggregate ABI) - As an optimization for both ELFv1 and ELFv2 ABIs, pass aggregates that fit fully in registers without using the "byval" mechanism The patch uses the functionArgumentNeedsConsecutiveRegisters callback to encode that special treatment is required for all directly-passed array types. The isInConsecutiveRegs / isInConsecutiveRegsLast bits set as a results are then used to implement the required size and alignment rules in CalculateStackSlotSize / CalculateStackSlotAlignment etc. As a related change, the ABI routines have to be modified to support passing floating-point types in GPRs. This is necessary because with homogeneous aggregates of 4-byte float type we can now run out of FPRs *before* we run out of the 64-byte argument save area that is shadowed by GPRs. Any extra floating-point arguments that no longer fit in FPRs must now be passed in GPRs until we run out of those too. Note that there was already code to pass floating-point arguments in GPRs used with vararg parameters, which was done by writing the argument out to the argument save area first and then reloading into GPRs. The patch re-implements this, however, in favor of code packing float arguments directly via extension/truncation, BITCAST, and BUILD_PAIR operations. This is required to support the ELFv2 ABI, since we cannot unconditionally write to the argument save area (which the caller might not have allocated). The change does, however, affect ELFv1 varags routines too; but even here the overall effect should be advantageous: Instead of loading the argument into the FPR, then storing the argument to the stack slot, and finally reloading the argument from the stack slot into a GPR, the new code now just loads the argument into the FPR, and subsequently loads the argument into the GPR (via BITCAST). That BITCAST might imply a save/reload from a stack temporary (in which case we're no worse than before); but it might be implemented more efficiently in some cases. The final part of the patch enables up to 8 FPRs and VRs for argument return in PPCCallingConv.td; this is required to support returning ELFv2 homogeneous aggregates. (Note that this doesn't affect other ABIs since LLVM wil only look for which register to use if the parameter is marked as "direct" return anyway.) Reviewed by Hal Finkel. llvm-svn: 213493
2014-07-21 08:13:26 +08:00
/// \brief Returns true if an argument of type Ty needs to be passed in a
/// contiguous block of registers in calling convention CallConv.
bool functionArgumentNeedsConsecutiveRegisters(
Type *Ty, CallingConv::ID CallConv, bool isVarArg) const override {
// We support any array type as "consecutive" block in the parameter
// save area. The element type defines the alignment requirement and
// whether the argument should go in GPRs, FPRs, or VRs if available.
//
// Note that clang uses this capability both to implement the ELFv2
// homogeneous float/vector aggregate ABI, and to avoid having to use
// "byval" when passing aggregates that might fully fit in registers.
return Ty->isArrayTy();
}
private:
struct ReuseLoadInfo {
SDValue Ptr;
SDValue Chain;
SDValue ResChain;
MachinePointerInfo MPI;
bool IsInvariant;
unsigned Alignment;
AAMDNodes AAInfo;
const MDNode *Ranges;
ReuseLoadInfo() : IsInvariant(false), Alignment(0), Ranges(nullptr) {}
};
bool canReuseLoadAddress(SDValue Op, EVT MemVT, ReuseLoadInfo &RLI,
SelectionDAG &DAG,
ISD::LoadExtType ET = ISD::NON_EXTLOAD) const;
void spliceIntoChain(SDValue ResChain, SDValue NewResChain,
SelectionDAG &DAG) const;
void LowerFP_TO_INTForReuse(SDValue Op, ReuseLoadInfo &RLI,
SelectionDAG &DAG, SDLoc dl) const;
SDValue LowerFP_TO_INTDirectMove(SDValue Op, SelectionDAG &DAG,
SDLoc dl) const;
SDValue LowerINT_TO_FPDirectMove(SDValue Op, SelectionDAG &DAG,
SDLoc dl) const;
SDValue getFramePointerFrameIndex(SelectionDAG & DAG) const;
SDValue getReturnAddrFrameIndex(SelectionDAG & DAG) const;
bool
IsEligibleForTailCallOptimization(SDValue Callee,
CallingConv::ID CalleeCC,
bool isVarArg,
const SmallVectorImpl<ISD::InputArg> &Ins,
SelectionDAG& DAG) const;
SDValue EmitTailCallLoadFPAndRetAddr(SelectionDAG & DAG,
int SPDiff,
SDValue Chain,
SDValue &LROpOut,
SDValue &FPOpOut,
bool isDarwinABI,
SDLoc dl) const;
SDValue LowerRETURNADDR(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerFRAMEADDR(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerConstantPool(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerBlockAddress(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerGlobalAddress(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerJumpTable(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerSETCC(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerINIT_TRAMPOLINE(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerADJUST_TRAMPOLINE(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerVASTART(SDValue Op, SelectionDAG &DAG,
const PPCSubtarget &Subtarget) const;
SDValue LowerVAARG(SDValue Op, SelectionDAG &DAG,
const PPCSubtarget &Subtarget) const;
SDValue LowerVACOPY(SDValue Op, SelectionDAG &DAG,
const PPCSubtarget &Subtarget) const;
SDValue LowerSTACKRESTORE(SDValue Op, SelectionDAG &DAG,
const PPCSubtarget &Subtarget) const;
SDValue LowerDYNAMIC_STACKALLOC(SDValue Op, SelectionDAG &DAG,
const PPCSubtarget &Subtarget) const;
Add CR-bit tracking to the PowerPC backend for i1 values This change enables tracking i1 values in the PowerPC backend using the condition register bits. These bits can be treated on PowerPC as separate registers; individual bit operations (and, or, xor, etc.) are supported. Tracking booleans in CR bits has several advantages: - Reduction in register pressure (because we no longer need GPRs to store boolean values). - Logical operations on booleans can be handled more efficiently; we used to have to move all results from comparisons into GPRs, perform promoted logical operations in GPRs, and then move the result back into condition register bits to be used by conditional branches. This can be very inefficient, because the throughput of these CR <-> GPR moves have high latency and low throughput (especially when other associated instructions are accounted for). - On the POWER7 and similar cores, we can increase total throughput by using the CR bits. CR bit operations have a dedicated functional unit. Most of this is more-or-less mechanical: Adjustments were needed in the calling-convention code, support was added for spilling/restoring individual condition-register bits, and conditional branch instruction definitions taking specific CR bits were added (plus patterns and code for generating bit-level operations). This is enabled by default when running at -O2 and higher. For -O0 and -O1, where the ability to debug is more important, this feature is disabled by default. Individual CR bits do not have assigned DWARF register numbers, and storing values in CR bits makes them invisible to the debugger. It is critical, however, that we don't move i1 values that have been promoted to larger values (such as those passed as function arguments) into bit registers only to quickly turn around and move the values back into GPRs (such as happens when values are returned by functions). A pair of target-specific DAG combines are added to remove the trunc/extends in: trunc(binary-ops(binary-ops(zext(x), zext(y)), ...) and: zext(binary-ops(binary-ops(trunc(x), trunc(y)), ...) In short, we only want to use CR bits where some of the i1 values come from comparisons or are used by conditional branches or selects. To put it another way, if we can do the entire i1 computation in GPRs, then we probably should (on the POWER7, the GPR-operation throughput is higher, and for all cores, the CR <-> GPR moves are expensive). POWER7 test-suite performance results (from 10 runs in each configuration): SingleSource/Benchmarks/Misc/mandel-2: 35% speedup MultiSource/Benchmarks/Prolangs-C++/city/city: 21% speedup MultiSource/Benchmarks/MiBench/automotive-susan: 23% speedup SingleSource/Benchmarks/CoyoteBench/huffbench: 13% speedup SingleSource/Benchmarks/Misc-C++/Large/sphereflake: 13% speedup SingleSource/Benchmarks/Misc-C++/mandel-text: 10% speedup SingleSource/Benchmarks/Misc-C++-EH/spirit: 10% slowdown MultiSource/Applications/lemon/lemon: 8% slowdown llvm-svn: 202451
2014-02-28 08:27:01 +08:00
SDValue LowerLOAD(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerSTORE(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerTRUNCATE(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerSELECT_CC(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerFP_TO_INT(SDValue Op, SelectionDAG &DAG, SDLoc dl) const;
SDValue LowerINT_TO_FP(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerFLT_ROUNDS_(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerSHL_PARTS(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerSRL_PARTS(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerSRA_PARTS(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerBUILD_VECTOR(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerVECTOR_SHUFFLE(SDValue Op, SelectionDAG &DAG) const;
2015-02-25 09:06:45 +08:00
SDValue LowerEXTRACT_VECTOR_ELT(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerINTRINSIC_WO_CHAIN(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerSCALAR_TO_VECTOR(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerSIGN_EXTEND_INREG(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerMUL(SDValue Op, SelectionDAG &DAG) const;
2015-02-25 09:06:45 +08:00
SDValue LowerVectorLoad(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerVectorStore(SDValue Op, SelectionDAG &DAG) const;
SDValue LowerCallResult(SDValue Chain, SDValue InFlag,
CallingConv::ID CallConv, bool isVarArg,
const SmallVectorImpl<ISD::InputArg> &Ins,
SDLoc dl, SelectionDAG &DAG,
SmallVectorImpl<SDValue> &InVals) const;
SDValue FinishCall(CallingConv::ID CallConv, SDLoc dl, bool isTailCall,
bool isVarArg, bool IsPatchPoint,
SelectionDAG &DAG,
SmallVector<std::pair<unsigned, SDValue>, 8>
&RegsToPass,
[PowerPC] Loosen ELFv1 PPC64 func descriptor loads for indirect calls Function pointers under PPC64 ELFv1 (which is used on PPC64/Linux on the POWER7, A2 and earlier cores) are really pointers to a function descriptor, a structure with three pointers: the actual pointer to the code to which to jump, the pointer to the TOC needed by the callee, and an environment pointer. We used to chain these loads, and make them opaque to the rest of the optimizer, so that they'd always occur directly before the call. This is not necessary, and in fact, highly suboptimal on embedded cores. Once the function pointer is known, the loads can be performed ahead of time; in fact, they can be hoisted out of loops. Now these function descriptors are almost always generated by the linker, and thus the contents of the descriptors are invariant. As a result, by default, we'll mark the associated loads as invariant (allowing them to be hoisted out of loops). I've added a target feature to turn this off, however, just in case someone needs that option (constructing an on-stack descriptor, casting it to a function pointer, and then calling it cannot be well-defined C/C++ code, but I can imagine some JIT-compilation system doing so). Consider this simple test: $ cat call.c typedef void (*fp)(); void bar(fp x) { for (int i = 0; i < 1600000000; ++i) x(); } $ cat main.c typedef void (*fp)(); void bar(fp x); void foo() {} int main() { bar(foo); } On the PPC A2 (the BG/Q supercomputer), marking the function-descriptor loads as invariant brings the execution time down to ~8 seconds from ~32 seconds with the loads in the loop. The difference on the POWER7 is smaller. Compiling with: gcc -std=c99 -O3 -mcpu=native call.c main.c : ~6 seconds [this is 4.8.2] clang -O3 -mcpu=native call.c main.c : ~5.3 seconds clang -O3 -mcpu=native call.c main.c -mno-invariant-function-descriptors : ~4 seconds (looks like we'd benefit from additional loop unrolling here, as a first guess, because this is faster with the extra loads) The -mno-invariant-function-descriptors will be added to Clang shortly. llvm-svn: 226207
2015-01-16 05:17:34 +08:00
SDValue InFlag, SDValue Chain, SDValue CallSeqStart,
SDValue &Callee,
int SPDiff, unsigned NumBytes,
const SmallVectorImpl<ISD::InputArg> &Ins,
[PowerPC] Loosen ELFv1 PPC64 func descriptor loads for indirect calls Function pointers under PPC64 ELFv1 (which is used on PPC64/Linux on the POWER7, A2 and earlier cores) are really pointers to a function descriptor, a structure with three pointers: the actual pointer to the code to which to jump, the pointer to the TOC needed by the callee, and an environment pointer. We used to chain these loads, and make them opaque to the rest of the optimizer, so that they'd always occur directly before the call. This is not necessary, and in fact, highly suboptimal on embedded cores. Once the function pointer is known, the loads can be performed ahead of time; in fact, they can be hoisted out of loops. Now these function descriptors are almost always generated by the linker, and thus the contents of the descriptors are invariant. As a result, by default, we'll mark the associated loads as invariant (allowing them to be hoisted out of loops). I've added a target feature to turn this off, however, just in case someone needs that option (constructing an on-stack descriptor, casting it to a function pointer, and then calling it cannot be well-defined C/C++ code, but I can imagine some JIT-compilation system doing so). Consider this simple test: $ cat call.c typedef void (*fp)(); void bar(fp x) { for (int i = 0; i < 1600000000; ++i) x(); } $ cat main.c typedef void (*fp)(); void bar(fp x); void foo() {} int main() { bar(foo); } On the PPC A2 (the BG/Q supercomputer), marking the function-descriptor loads as invariant brings the execution time down to ~8 seconds from ~32 seconds with the loads in the loop. The difference on the POWER7 is smaller. Compiling with: gcc -std=c99 -O3 -mcpu=native call.c main.c : ~6 seconds [this is 4.8.2] clang -O3 -mcpu=native call.c main.c : ~5.3 seconds clang -O3 -mcpu=native call.c main.c -mno-invariant-function-descriptors : ~4 seconds (looks like we'd benefit from additional loop unrolling here, as a first guess, because this is faster with the extra loads) The -mno-invariant-function-descriptors will be added to Clang shortly. llvm-svn: 226207
2015-01-16 05:17:34 +08:00
SmallVectorImpl<SDValue> &InVals,
ImmutableCallSite *CS) const;
SDValue
LowerFormalArguments(SDValue Chain,
CallingConv::ID CallConv, bool isVarArg,
const SmallVectorImpl<ISD::InputArg> &Ins,
SDLoc dl, SelectionDAG &DAG,
SmallVectorImpl<SDValue> &InVals) const override;
SDValue
LowerCall(TargetLowering::CallLoweringInfo &CLI,
SmallVectorImpl<SDValue> &InVals) const override;
bool
CanLowerReturn(CallingConv::ID CallConv, MachineFunction &MF,
bool isVarArg,
const SmallVectorImpl<ISD::OutputArg> &Outs,
LLVMContext &Context) const override;
SDValue
LowerReturn(SDValue Chain,
CallingConv::ID CallConv, bool isVarArg,
const SmallVectorImpl<ISD::OutputArg> &Outs,
const SmallVectorImpl<SDValue> &OutVals,
SDLoc dl, SelectionDAG &DAG) const override;
SDValue
extendArgForPPC64(ISD::ArgFlagsTy Flags, EVT ObjectVT, SelectionDAG &DAG,
SDValue ArgVal, SDLoc dl) const;
SDValue
LowerFormalArguments_Darwin(SDValue Chain,
CallingConv::ID CallConv, bool isVarArg,
const SmallVectorImpl<ISD::InputArg> &Ins,
SDLoc dl, SelectionDAG &DAG,
SmallVectorImpl<SDValue> &InVals) const;
SDValue
LowerFormalArguments_64SVR4(SDValue Chain,
CallingConv::ID CallConv, bool isVarArg,
const SmallVectorImpl<ISD::InputArg> &Ins,
SDLoc dl, SelectionDAG &DAG,
SmallVectorImpl<SDValue> &InVals) const;
SDValue
LowerFormalArguments_32SVR4(SDValue Chain,
CallingConv::ID CallConv, bool isVarArg,
const SmallVectorImpl<ISD::InputArg> &Ins,
SDLoc dl, SelectionDAG &DAG,
SmallVectorImpl<SDValue> &InVals) const;
SDValue
createMemcpyOutsideCallSeq(SDValue Arg, SDValue PtrOff,
SDValue CallSeqStart, ISD::ArgFlagsTy Flags,
SelectionDAG &DAG, SDLoc dl) const;
SDValue
LowerCall_Darwin(SDValue Chain, SDValue Callee,
CallingConv::ID CallConv,
bool isVarArg, bool isTailCall, bool IsPatchPoint,
const SmallVectorImpl<ISD::OutputArg> &Outs,
const SmallVectorImpl<SDValue> &OutVals,
const SmallVectorImpl<ISD::InputArg> &Ins,
SDLoc dl, SelectionDAG &DAG,
[PowerPC] Loosen ELFv1 PPC64 func descriptor loads for indirect calls Function pointers under PPC64 ELFv1 (which is used on PPC64/Linux on the POWER7, A2 and earlier cores) are really pointers to a function descriptor, a structure with three pointers: the actual pointer to the code to which to jump, the pointer to the TOC needed by the callee, and an environment pointer. We used to chain these loads, and make them opaque to the rest of the optimizer, so that they'd always occur directly before the call. This is not necessary, and in fact, highly suboptimal on embedded cores. Once the function pointer is known, the loads can be performed ahead of time; in fact, they can be hoisted out of loops. Now these function descriptors are almost always generated by the linker, and thus the contents of the descriptors are invariant. As a result, by default, we'll mark the associated loads as invariant (allowing them to be hoisted out of loops). I've added a target feature to turn this off, however, just in case someone needs that option (constructing an on-stack descriptor, casting it to a function pointer, and then calling it cannot be well-defined C/C++ code, but I can imagine some JIT-compilation system doing so). Consider this simple test: $ cat call.c typedef void (*fp)(); void bar(fp x) { for (int i = 0; i < 1600000000; ++i) x(); } $ cat main.c typedef void (*fp)(); void bar(fp x); void foo() {} int main() { bar(foo); } On the PPC A2 (the BG/Q supercomputer), marking the function-descriptor loads as invariant brings the execution time down to ~8 seconds from ~32 seconds with the loads in the loop. The difference on the POWER7 is smaller. Compiling with: gcc -std=c99 -O3 -mcpu=native call.c main.c : ~6 seconds [this is 4.8.2] clang -O3 -mcpu=native call.c main.c : ~5.3 seconds clang -O3 -mcpu=native call.c main.c -mno-invariant-function-descriptors : ~4 seconds (looks like we'd benefit from additional loop unrolling here, as a first guess, because this is faster with the extra loads) The -mno-invariant-function-descriptors will be added to Clang shortly. llvm-svn: 226207
2015-01-16 05:17:34 +08:00
SmallVectorImpl<SDValue> &InVals,
ImmutableCallSite *CS) const;
SDValue
LowerCall_64SVR4(SDValue Chain, SDValue Callee,
CallingConv::ID CallConv,
bool isVarArg, bool isTailCall, bool IsPatchPoint,
const SmallVectorImpl<ISD::OutputArg> &Outs,
const SmallVectorImpl<SDValue> &OutVals,
const SmallVectorImpl<ISD::InputArg> &Ins,
SDLoc dl, SelectionDAG &DAG,
[PowerPC] Loosen ELFv1 PPC64 func descriptor loads for indirect calls Function pointers under PPC64 ELFv1 (which is used on PPC64/Linux on the POWER7, A2 and earlier cores) are really pointers to a function descriptor, a structure with three pointers: the actual pointer to the code to which to jump, the pointer to the TOC needed by the callee, and an environment pointer. We used to chain these loads, and make them opaque to the rest of the optimizer, so that they'd always occur directly before the call. This is not necessary, and in fact, highly suboptimal on embedded cores. Once the function pointer is known, the loads can be performed ahead of time; in fact, they can be hoisted out of loops. Now these function descriptors are almost always generated by the linker, and thus the contents of the descriptors are invariant. As a result, by default, we'll mark the associated loads as invariant (allowing them to be hoisted out of loops). I've added a target feature to turn this off, however, just in case someone needs that option (constructing an on-stack descriptor, casting it to a function pointer, and then calling it cannot be well-defined C/C++ code, but I can imagine some JIT-compilation system doing so). Consider this simple test: $ cat call.c typedef void (*fp)(); void bar(fp x) { for (int i = 0; i < 1600000000; ++i) x(); } $ cat main.c typedef void (*fp)(); void bar(fp x); void foo() {} int main() { bar(foo); } On the PPC A2 (the BG/Q supercomputer), marking the function-descriptor loads as invariant brings the execution time down to ~8 seconds from ~32 seconds with the loads in the loop. The difference on the POWER7 is smaller. Compiling with: gcc -std=c99 -O3 -mcpu=native call.c main.c : ~6 seconds [this is 4.8.2] clang -O3 -mcpu=native call.c main.c : ~5.3 seconds clang -O3 -mcpu=native call.c main.c -mno-invariant-function-descriptors : ~4 seconds (looks like we'd benefit from additional loop unrolling here, as a first guess, because this is faster with the extra loads) The -mno-invariant-function-descriptors will be added to Clang shortly. llvm-svn: 226207
2015-01-16 05:17:34 +08:00
SmallVectorImpl<SDValue> &InVals,
ImmutableCallSite *CS) const;
SDValue
LowerCall_32SVR4(SDValue Chain, SDValue Callee, CallingConv::ID CallConv,
bool isVarArg, bool isTailCall, bool IsPatchPoint,
const SmallVectorImpl<ISD::OutputArg> &Outs,
const SmallVectorImpl<SDValue> &OutVals,
const SmallVectorImpl<ISD::InputArg> &Ins,
SDLoc dl, SelectionDAG &DAG,
[PowerPC] Loosen ELFv1 PPC64 func descriptor loads for indirect calls Function pointers under PPC64 ELFv1 (which is used on PPC64/Linux on the POWER7, A2 and earlier cores) are really pointers to a function descriptor, a structure with three pointers: the actual pointer to the code to which to jump, the pointer to the TOC needed by the callee, and an environment pointer. We used to chain these loads, and make them opaque to the rest of the optimizer, so that they'd always occur directly before the call. This is not necessary, and in fact, highly suboptimal on embedded cores. Once the function pointer is known, the loads can be performed ahead of time; in fact, they can be hoisted out of loops. Now these function descriptors are almost always generated by the linker, and thus the contents of the descriptors are invariant. As a result, by default, we'll mark the associated loads as invariant (allowing them to be hoisted out of loops). I've added a target feature to turn this off, however, just in case someone needs that option (constructing an on-stack descriptor, casting it to a function pointer, and then calling it cannot be well-defined C/C++ code, but I can imagine some JIT-compilation system doing so). Consider this simple test: $ cat call.c typedef void (*fp)(); void bar(fp x) { for (int i = 0; i < 1600000000; ++i) x(); } $ cat main.c typedef void (*fp)(); void bar(fp x); void foo() {} int main() { bar(foo); } On the PPC A2 (the BG/Q supercomputer), marking the function-descriptor loads as invariant brings the execution time down to ~8 seconds from ~32 seconds with the loads in the loop. The difference on the POWER7 is smaller. Compiling with: gcc -std=c99 -O3 -mcpu=native call.c main.c : ~6 seconds [this is 4.8.2] clang -O3 -mcpu=native call.c main.c : ~5.3 seconds clang -O3 -mcpu=native call.c main.c -mno-invariant-function-descriptors : ~4 seconds (looks like we'd benefit from additional loop unrolling here, as a first guess, because this is faster with the extra loads) The -mno-invariant-function-descriptors will be added to Clang shortly. llvm-svn: 226207
2015-01-16 05:17:34 +08:00
SmallVectorImpl<SDValue> &InVals,
ImmutableCallSite *CS) const;
SDValue lowerEH_SJLJ_SETJMP(SDValue Op, SelectionDAG &DAG) const;
SDValue lowerEH_SJLJ_LONGJMP(SDValue Op, SelectionDAG &DAG) const;
Add CR-bit tracking to the PowerPC backend for i1 values This change enables tracking i1 values in the PowerPC backend using the condition register bits. These bits can be treated on PowerPC as separate registers; individual bit operations (and, or, xor, etc.) are supported. Tracking booleans in CR bits has several advantages: - Reduction in register pressure (because we no longer need GPRs to store boolean values). - Logical operations on booleans can be handled more efficiently; we used to have to move all results from comparisons into GPRs, perform promoted logical operations in GPRs, and then move the result back into condition register bits to be used by conditional branches. This can be very inefficient, because the throughput of these CR <-> GPR moves have high latency and low throughput (especially when other associated instructions are accounted for). - On the POWER7 and similar cores, we can increase total throughput by using the CR bits. CR bit operations have a dedicated functional unit. Most of this is more-or-less mechanical: Adjustments were needed in the calling-convention code, support was added for spilling/restoring individual condition-register bits, and conditional branch instruction definitions taking specific CR bits were added (plus patterns and code for generating bit-level operations). This is enabled by default when running at -O2 and higher. For -O0 and -O1, where the ability to debug is more important, this feature is disabled by default. Individual CR bits do not have assigned DWARF register numbers, and storing values in CR bits makes them invisible to the debugger. It is critical, however, that we don't move i1 values that have been promoted to larger values (such as those passed as function arguments) into bit registers only to quickly turn around and move the values back into GPRs (such as happens when values are returned by functions). A pair of target-specific DAG combines are added to remove the trunc/extends in: trunc(binary-ops(binary-ops(zext(x), zext(y)), ...) and: zext(binary-ops(binary-ops(trunc(x), trunc(y)), ...) In short, we only want to use CR bits where some of the i1 values come from comparisons or are used by conditional branches or selects. To put it another way, if we can do the entire i1 computation in GPRs, then we probably should (on the POWER7, the GPR-operation throughput is higher, and for all cores, the CR <-> GPR moves are expensive). POWER7 test-suite performance results (from 10 runs in each configuration): SingleSource/Benchmarks/Misc/mandel-2: 35% speedup MultiSource/Benchmarks/Prolangs-C++/city/city: 21% speedup MultiSource/Benchmarks/MiBench/automotive-susan: 23% speedup SingleSource/Benchmarks/CoyoteBench/huffbench: 13% speedup SingleSource/Benchmarks/Misc-C++/Large/sphereflake: 13% speedup SingleSource/Benchmarks/Misc-C++/mandel-text: 10% speedup SingleSource/Benchmarks/Misc-C++-EH/spirit: 10% slowdown MultiSource/Applications/lemon/lemon: 8% slowdown llvm-svn: 202451
2014-02-28 08:27:01 +08:00
SDValue DAGCombineExtBoolTrunc(SDNode *N, DAGCombinerInfo &DCI) const;
SDValue DAGCombineTruncBoolExt(SDNode *N, DAGCombinerInfo &DCI) const;
SDValue combineFPToIntToFP(SDNode *N, DAGCombinerInfo &DCI) const;
SDValue getRsqrtEstimate(SDValue Operand, DAGCombinerInfo &DCI,
unsigned &RefinementSteps,
bool &UseOneConstNR) const override;
SDValue getRecipEstimate(SDValue Operand, DAGCombinerInfo &DCI,
unsigned &RefinementSteps) const override;
bool combineRepeatedFPDivisors(unsigned NumUsers) const override;
CCAssignFn *useFastISelCCs(unsigned Flag) const;
};
namespace PPC {
FastISel *createFastISel(FunctionLoweringInfo &FuncInfo,
const TargetLibraryInfo *LibInfo);
}
bool CC_PPC32_SVR4_Custom_Dummy(unsigned &ValNo, MVT &ValVT, MVT &LocVT,
CCValAssign::LocInfo &LocInfo,
ISD::ArgFlagsTy &ArgFlags,
CCState &State);
bool CC_PPC32_SVR4_Custom_AlignArgRegs(unsigned &ValNo, MVT &ValVT,
MVT &LocVT,
CCValAssign::LocInfo &LocInfo,
ISD::ArgFlagsTy &ArgFlags,
CCState &State);
bool CC_PPC32_SVR4_Custom_AlignFPArgRegs(unsigned &ValNo, MVT &ValVT,
MVT &LocVT,
CCValAssign::LocInfo &LocInfo,
ISD::ArgFlagsTy &ArgFlags,
CCState &State);
}
#endif // LLVM_TARGET_POWERPC_PPC32ISELLOWERING_H