ARM: implement support for the UDF mnemonic

The UDF instruction is a reserved undefined instruction space.  The assembler
mnemonic was introduced with ARM ARM rev C.a.  The instruction is not predicated
and the immediate constant is ignored by the CPU.  Add support for the three
encodings for this instruction.

The changes to the invalid instruction test is due to the fact that the invalid
instructions actually overlap with the undefined instruction.  Introduction of
the new instruction results in a partial decode as an undefined sequence.  Drop
the tests as they are invalid instruction patterns anyways.

llvm-svn: 208751
This commit is contained in:
Saleem Abdulrasool 2014-05-14 03:47:39 +00:00
parent f0cf8fa941
commit 27351f2022
11 changed files with 135 additions and 41 deletions

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@ -1967,6 +1967,18 @@ def DBG : AI<(outs), (ins imm0_15:$opt), MiscFrm, NoItinerary, "dbg", "\t$opt",
let Inst{3-0} = opt;
}
// A8.8.247 UDF - Undefined (Encoding A1)
def UDF : AInoP<(outs), (ins imm0_65535:$imm16), MiscFrm, NoItinerary,
"udf", "\t$imm16", []> {
bits<16> imm16;
let Inst{31-28} = 0b1110; // AL
let Inst{27-25} = 0b011;
let Inst{24-20} = 0b11111;
let Inst{19-8} = imm16{15-4};
let Inst{7-4} = 0b1111;
let Inst{3-0} = imm16{3-0};
}
/*
* A5.4 Permanently UNDEFINED instructions.
*

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@ -1193,6 +1193,15 @@ def tTST : // A8.6.230
[(ARMcmpZ (and_su tGPR:$Rn, tGPR:$Rm), 0)]>,
Sched<[WriteALU]>;
// A8.8.247 UDF - Undefined (Encoding T1)
def tUDF : TI<(outs), (ins imm0_255:$imm8), IIC_Br, "udf\t$imm8", []>,
Encoding16 {
bits<8> imm8;
let Inst{15-12} = 0b1101;
let Inst{11-8} = 0b1110;
let Inst{7-0} = imm8;
}
// Zero-extend byte
def tUXTB : // A8.6.262
T1pIMiscEncode<{0,0,1,0,1,1,?}, (outs tGPR:$Rd), (ins tGPR:$Rm),

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@ -2407,6 +2407,19 @@ def t2UBFX: T2TwoRegBitFI<
let Inst{15} = 0;
}
// A8.8.247 UDF - Undefined (Encoding T2)
def t2UDF
: T2XI<(outs), (ins imm0_65535:$imm16), IIC_Br, "udf.w\t$imm16", []> {
bits<16> imm16;
let Inst{31-29} = 0b111;
let Inst{28-27} = 0b10;
let Inst{26-20} = 0b1111111;
let Inst{19-16} = imm16{15-12};
let Inst{15} = 0b1;
let Inst{14-12} = 0b010;
let Inst{11-0} = imm16{11-0};
}
// A8.6.18 BFI - Bitfield insert (Encoding T1)
let Constraints = "$src = $Rd" in {
def t2BFI : T2TwoRegBitFI<(outs rGPR:$Rd),

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@ -5094,8 +5094,9 @@ getMnemonicAcceptInfo(StringRef Mnemonic, StringRef FullInst,
if (Mnemonic == "bkpt" || Mnemonic == "cbnz" || Mnemonic == "setend" ||
Mnemonic == "cps" || Mnemonic == "it" || Mnemonic == "cbz" ||
Mnemonic == "trap" || Mnemonic == "hlt" || Mnemonic.startswith("crc32") ||
Mnemonic.startswith("cps") || Mnemonic.startswith("vsel") ||
Mnemonic == "trap" || Mnemonic == "hlt" || Mnemonic == "udf" ||
Mnemonic.startswith("crc32") || Mnemonic.startswith("cps") ||
Mnemonic.startswith("vsel") ||
Mnemonic == "vmaxnm" || Mnemonic == "vminnm" || Mnemonic == "vcvta" ||
Mnemonic == "vcvtn" || Mnemonic == "vcvtp" || Mnemonic == "vcvtm" ||
Mnemonic == "vrinta" || Mnemonic == "vrintn" || Mnemonic == "vrintp" ||

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@ -0,0 +1,19 @@
@ RUN: not llvm-mc -triple arm-eabi %s 2>&1 | FileCheck %s
.syntax unified
.text
.arm
undefined:
udfpl
@ CHECK: error: instruction 'udf' is not predicable, but condition code specified
@ CHECK: udfpl
@ CHECK: ^
udf #65536
@ CHECK: error: invalid operand for instruction
@ CHECK: udf #65536
@ CHECK: ^

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@ -0,0 +1,11 @@
@ RUN: llvm-mc -triple arm-eabi -show-encoding %s | FileCheck %s
.syntax unified
.text
.arm
undefined:
udf #0
@ CHECK: udf #0 @ encoding: [0xf0,0x00,0xf0,0xe7]

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@ -0,0 +1,25 @@
@ RUN: not llvm-mc -triple thumbv7-eabi -mattr +thumb2 %s 2>&1 | FileCheck %s
.syntax unified
.text
.thumb
undefined:
udfpl
@ CHECK: error: instruction 'udf' is not predicable, but condition code specified
@ CHECK: udfpl
@ CHECK: ^
udf #256
@ CHECK: error: instruction requires: arm-mode
@ CHECK: udf #256
@ CHECK: ^
udf.w #65536
@ CHECK: error: invalid operand for instruction
@ CHECK: udf.w #65536
@ CHECK: ^

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@ -0,0 +1,13 @@
@ RUN: llvm-mc -triple thumbv7-eabi -mattr +thumb2 -show-encoding %s | FileCheck %s
.syntax unified
.text
.thumb
undefined:
udf #0
udf.w #0
@ CHECK: udf #0 @ encoding: [0x00,0xde]
@ CHECK: udf.w #0 @ encoding: [0xf0,0xf7,0x00,0xa0]

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@ -0,0 +1,19 @@
@ RUN: not llvm-mc -triple thumbv6m-eabi %s 2>&1 | FileCheck %s
.syntax unified
.text
.thumb
undefined:
udfpl
@ CHECK: error: conditional execution not supported in Thumb1
@ CHECK: udfpl
@ CHECK: ^
udf #256
@ CHECK: error: instruction requires: arm-mode
@ CHECK: udf #256
@ CHECK: ^

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@ -0,0 +1,11 @@
@ RUN: llvm-mc -triple thumbv6m-eabi -show-encoding %s | FileCheck %s
.syntax unified
.text
.thumb
undefined:
udf #0
@ CHECK: udf #0 @ encoding: [0x00,0xde]

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@ -21,17 +21,6 @@
# CHECK: warning: invalid instruction encoding
# CHECK-NEXT: [0xaf 0xf7 0x44 0x8b]
# Opcode=2249 Name=tBcc Format=ARM_FORMAT_THUMBFRM(25)
# 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
# -------------------------------------------------------------------------------------------------
# | 0: 0: 0: 0| 0: 0: 0: 0| 0: 0: 0: 0| 0: 0: 0: 0| 1: 1: 0: 1| 1: 1: 1: 0| 0: 1: 1: 0| 1: 1: 1: 1|
# -------------------------------------------------------------------------------------------------
#
# if cond = '1110' then UNDEFINED
[0x6f 0xde]
# CHECK: invalid instruction encoding
# CHECK-NEXT: [0x6f 0xde]
#------------------------------------------------------------------------------
# Undefined encoding for it
#------------------------------------------------------------------------------
@ -248,34 +237,6 @@
# CHECK: warning: potentially undefined instruction encoding
# CHECK-NEXT: [0xe4 0xe9 0x02 0x46]
#------------------------------------------------------------------------------
# Undefined encodings for NEON/VFP instructions with invalid predicate bits
#------------------------------------------------------------------------------
# VABS
[0x40 0xde 0x00 0x0a]
# CHECK: invalid instruction encoding
# CHECK-NEXT: [0x40 0xde 0x00 0x0a]
# VMLA
[0xf0 0xde 0xe0 0x0b]
# CHECK: invalid instruction encoding
# CHECK-NEXT: [0xf0 0xde 0xe0 0x0b]
# VMOV/VDUP between scalar and core registers with invalid predicate bits (pred != 0b1110)
# VMOV
[0x00 0xde 0x10 0x0b]
# CHECK: invalid instruction encoding
# CHECK-NEXT: [0x00 0xde 0x10 0x0b]
# VDUP
[0xff 0xde 0xf0 0xfb]
# CHECK: invalid instruction encoding
# CHECK-NEXT: [0xff 0xde 0xf0 0xfb]
#------------------------------------------------------------------------------
# Undefined encodings for NEON vld instructions
#------------------------------------------------------------------------------