Summary:
In SelectionDAG, when a store is immediately chained to another store
to the same address, elide the first store as it has no observable
effects. This is causes small improvements dealing with intrinsics
lowered to stores.
Test notes:
* Many testcases overwrite store addresses multiple times and needed
minor changes, mainly making stores volatile to prevent the
optimization from optimizing the test away.
* Many X86 test cases optimized out instructions associated with
associated with va_start.
* Note that test_splat in CodeGen/AArch64/misched-stp.ll no longer has
dependencies to check and can probably be removed and potentially
replaced with another test.
Reviewers: rnk, john.brawn
Subscribers: aemerson, rengolin, qcolombet, jyknight, nemanjai, nhaehnle, javed.absar, llvm-commits
Differential Revision: https://reviews.llvm.org/D33206
llvm-svn: 303198
Minimum density for both optsize and non optsize are now options
-sparse-jump-table-density (default 10) for non optsize functions
-dense-jump-table-density (default 40) for optsize functions, which
matches the current default. This improves several benchmarks at google
at the cost of a small codesize increase. For code compiled with -Os,
the old behavior continues
llvm-svn: 264689
The C and C++ semantics for compare_exchange require it to return a bool
indicating success. This gets mapped to LLVM IR which follows each cmpxchg with
an icmp of the value loaded against the desired value.
When lowered to ldxr/stxr loops, this extra comparison is redundant: its
results are implicit in the control-flow of the function.
This commit makes two changes: it replaces that icmp with appropriate PHI
nodes, and then makes sure earlyCSE is called after expansion to actually make
use of the opportunities revealed.
I've also added -{arm,aarch64}-enable-atomic-tidy options, so that
existing fragile tests aren't perturbed too much by the change. Many
of them either rely on undef/unreachable too pervasively to be
restored to something well-defined (particularly while making sure
they test the same obscure assert from many years ago), or depend on a
particular CFG shape, which is disrupted by SimplifyCFG.
rdar://problem/16227836
llvm-svn: 209883
when the condition is constant. This optimization shouldn't be
necessary, because codegen shouldn't be able to find dead control
paths that the IR-level optimizer can't find. And it's undesirable,
because it encourages bugpoint to leave "br i1 false" branches
in its output. And it wasn't updating the CFG.
I updated all the tests I could, but some tests are too reduced
and I wasn't able to meaningfully preserve them.
llvm-svn: 106748
instructions to help disassembly.
We also changed the output of the addressing modes to omit the '+' from the
assembler syntax #+/-<imm> or +/-<Rm>. See, for example, A8.6.57/58/60.
And modified test cases to not expect '+' in +reg or #+num. For example,
; CHECK: ldr.w r9, [r7, #28]
llvm-svn: 98745
U test/CodeGen/ARM/tls2.ll
U test/CodeGen/ARM/arm-negative-stride.ll
U test/CodeGen/ARM/2009-10-30.ll
U test/CodeGen/ARM/globals.ll
U test/CodeGen/ARM/str_pre-2.ll
U test/CodeGen/ARM/ldrd.ll
U test/CodeGen/ARM/2009-10-27-double-align.ll
U test/CodeGen/Thumb2/thumb2-strb.ll
U test/CodeGen/Thumb2/ldr-str-imm12.ll
U test/CodeGen/Thumb2/thumb2-strh.ll
U test/CodeGen/Thumb2/thumb2-ldr.ll
U test/CodeGen/Thumb2/thumb2-str_pre.ll
U test/CodeGen/Thumb2/thumb2-str.ll
U test/CodeGen/Thumb2/thumb2-ldrh.ll
U utils/TableGen/TableGen.cpp
U utils/TableGen/DisassemblerEmitter.cpp
D utils/TableGen/RISCDisassemblerEmitter.h
D utils/TableGen/RISCDisassemblerEmitter.cpp
U Makefile.rules
U lib/Target/ARM/ARMInstrNEON.td
U lib/Target/ARM/Makefile
U lib/Target/ARM/AsmPrinter/ARMInstPrinter.cpp
U lib/Target/ARM/AsmPrinter/ARMAsmPrinter.cpp
U lib/Target/ARM/AsmPrinter/ARMInstPrinter.h
D lib/Target/ARM/Disassembler
U lib/Target/ARM/ARMInstrFormats.td
U lib/Target/ARM/ARMAddressingModes.h
U lib/Target/ARM/Thumb2ITBlockPass.cpp
llvm-svn: 98640
(RISCDisassemblerEmitter) which emits the decoder functions for ARM and Thumb,
and the disassembler core which invokes the decoder function and builds up the
MCInst based on the decoded Opcode.
Added sub-formats to the NeonI/NeonXI instructions to further refine the NEONFrm
instructions to help disassembly.
We also changed the output of the addressing modes to omit the '+' from the
assembler syntax #+/-<imm> or +/-<Rm>. See, for example, A8.6.57/58/60.
And modified test cases to not expect '+' in +reg or #+num. For example,
; CHECK: ldr.w r9, [r7, #28]
llvm-svn: 98637
Nirav Dave