For now, avoid issuing extract_subreg to reuse lower 8-bit, it's not safe in 32-bit.

llvm-svn: 93307
2010-01-13 08:01:32 +00:00 · 2010-01-13 08:01:32 +00:00 · ceb5a4e8f6
parent 957b8beaaa
commit ceb5a4e8f6
1 changed files with 4 additions and 0 deletions
--- a/llvm/lib/Target/X86/X86InstrInfo.cpp
+++ b/llvm/lib/Target/X86/X86InstrInfo.cpp
@ -724,6 +724,10 @@ X86InstrInfo::isCoalescableExtInstr(const MachineInstr &MI,
  case X86::MOVZX32rr8:
  case X86::MOVSX64rr8:
  case X86::MOVZX64rr8:
+    if (!TM.getSubtarget<X86Subtarget>().is64Bit())
+      // It's not always legal to reference the low 8-bit of the larger
+      // register in 32-bit mode.
+      return false;
  case X86::MOVSX32rr16:
  case X86::MOVZX32rr16:
  case X86::MOVSX64rr16: