Ignore metainstructions during the shrink wrap analysis
Shrink wrapping should ignore DBG_VALUEs referring to frame indices,
since the presence of debug information must not affect code
generation.
Differential Revision: https://reviews.llvm.org/D41187
llvm-svn: 320606
diff --git a/llvm/lib/CodeGen/ShrinkWrap.cpp b/llvm/lib/CodeGen/ShrinkWrap.cpp
index ed01a90..2d90129 100644
--- a/llvm/lib/CodeGen/ShrinkWrap.cpp
+++ b/llvm/lib/CodeGen/ShrinkWrap.cpp
@@ -240,6 +240,10 @@
bool ShrinkWrap::useOrDefCSROrFI(const MachineInstr &MI,
RegScavenger *RS) const {
+ // Ignore DBG_VALUE and other meta instructions that must not affect codegen.
+ if (MI.isMetaInstruction())
+ return false;
+
if (MI.getOpcode() == FrameSetupOpcode ||
MI.getOpcode() == FrameDestroyOpcode) {
DEBUG(dbgs() << "Frame instruction: " << MI << '\n');