[GlobalISel][Legalizer] Fix lowerSelect() not sign-extending the mask value.
I'm not sure why the SEXT_INREG was gated on a bitwidth check of the mask
vs element size.
This fixes a miscompile in chromium's skia library.
Differential Revision: https://reviews.llvm.org/D134236
diff --git a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
index 2a45cff..2b9bc22 100644
--- a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
@@ -7247,10 +7247,8 @@
// The condition was potentially zero extended before, but we want a sign
// extended boolean.
- if (MaskTy.getSizeInBits() <= DstTy.getScalarSizeInBits() &&
- MaskTy != LLT::scalar(1)) {
+ if (MaskTy != LLT::scalar(1))
MaskElt = MIRBuilder.buildSExtInReg(MaskTy, MaskElt, 1).getReg(0);
- }
// Continue the sign extension (or truncate) to match the data type.
MaskElt = MIRBuilder.buildSExtOrTrunc(DstTy.getElementType(),
