From 97c37bb4d4ae5e505350091e520a1354069941e0 Mon Sep 17 00:00:00 2001 From: Jim Grosbach Date: Tue, 9 Jul 2013 22:59:22 +0000 Subject: 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 --- lib/Target/ARM/ARMInstrThumb2.td | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'lib/Target/ARM') diff --git a/lib/Target/ARM/ARMInstrThumb2.td b/lib/Target/ARM/ARMInstrThumb2.td index d71824e..ee9eaaa 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), -- cgit v1.1