diff options
Diffstat (limited to 'llvm/lib/Target/AMDGPU/SIISelLowering.cpp')
| -rw-r--r-- | llvm/lib/Target/AMDGPU/SIISelLowering.cpp | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/llvm/lib/Target/AMDGPU/SIISelLowering.cpp b/llvm/lib/Target/AMDGPU/SIISelLowering.cpp index 1bc430b3e06..7f1467c48dd 100644 --- a/llvm/lib/Target/AMDGPU/SIISelLowering.cpp +++ b/llvm/lib/Target/AMDGPU/SIISelLowering.cpp @@ -5983,11 +5983,18 @@ std::pair<SDValue, SDValue> SITargetLowering::splitBufferOffsets( if (C1) { unsigned ImmOffset = C1->getZExtValue(); // If the immediate value is too big for the immoffset field, put the value - // mod 4096 into the immoffset field so that the value that is copied/added + // and -4096 into the immoffset field so that the value that is copied/added // for the voffset field is a multiple of 4096, and it stands more chance // of being CSEd with the copy/add for another similar load/store. + // However, do not do that rounding down to a multiple of 4096 if that is a + // negative number, as it appears to be illegal to have a negative offset + // in the vgpr, even if adding the immediate offset makes it positive. unsigned Overflow = ImmOffset & ~MaxImm; ImmOffset -= Overflow; + if ((int32_t)Overflow < 0) { + Overflow += ImmOffset; + ImmOffset = 0; + } C1 = cast<ConstantSDNode>(DAG.getConstant(ImmOffset, DL, MVT::i32)); if (Overflow) { auto OverflowVal = DAG.getConstant(Overflow, DL, MVT::i32); |
