diff options
| author | Jim Grosbach <grosbach@apple.com> | 2013-07-09 22:59:22 +0000 |
|---|---|---|
| committer | Jim Grosbach <grosbach@apple.com> | 2013-07-09 22:59:22 +0000 |
| commit | 97c37bb4d4ae5e505350091e520a1354069941e0 (patch) | |
| tree | adc2a90a1ecc0d70e7d18e0dd0031e4f519b0444 /lib/Target/ARM/ARMInstrThumb2.td | |
| parent | 46e11c4c97fe1c424241e4098801456303a5c86e (diff) | |
| download | llvm-97c37bb4d4ae5e505350091e520a1354069941e0.tar.gz llvm-97c37bb4d4ae5e505350091e520a1354069941e0.tar.bz2 llvm-97c37bb4d4ae5e505350091e520a1354069941e0.tar.xz | |
ARM: Fix incorrect pack pattern for thumb2
Propagate the fix from r185712 to Thumb2 codegen as well. Original
commit message applies here as well:
A "pkhtb x, x, y asr #num" uses the lower 16 bits of "y asr #num" and
packs them in the bottom half of "x". An arithmetic and logic shift are
only equivalent in this context if the shift amount is 16. We would be
shifting in ones into the bottom 16bits instead of zeros if "y" is
negative.
rdar://14338767
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185982 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Target/ARM/ARMInstrThumb2.td')
| -rw-r--r-- | lib/Target/ARM/ARMInstrThumb2.td | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/lib/Target/ARM/ARMInstrThumb2.td b/lib/Target/ARM/ARMInstrThumb2.td index d71824e3c6..ee9eaaab31 100644 --- a/lib/Target/ARM/ARMInstrThumb2.td +++ b/lib/Target/ARM/ARMInstrThumb2.td @@ -2951,7 +2951,12 @@ def t2PKHTB : T2ThreeReg< // Alternate cases for PKHTB where identities eliminate some nodes. Note that // a shift amount of 0 is *not legal* here, it is PKHBT instead. -def : T2Pat<(or (and rGPR:$src1, 0xFFFF0000), (srl rGPR:$src2, imm16_31:$sh)), +// We also can not replace a srl (17..31) by an arithmetic shift we would use in +// pkhtb src1, src2, asr (17..31). +def : T2Pat<(or (and rGPR:$src1, 0xFFFF0000), (srl rGPR:$src2, imm16:$sh)), + (t2PKHTB rGPR:$src1, rGPR:$src2, imm16:$sh)>, + Requires<[HasT2ExtractPack, IsThumb2]>; +def : T2Pat<(or (and rGPR:$src1, 0xFFFF0000), (sra rGPR:$src2, imm16_31:$sh)), (t2PKHTB rGPR:$src1, rGPR:$src2, imm16_31:$sh)>, Requires<[HasT2ExtractPack, IsThumb2]>; def : T2Pat<(or (and rGPR:$src1, 0xFFFF0000), |