[X86] Reject dirflag in inline asm constraints other than clobber.

Fixes the crash from PR47195.

diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index 961fd08..05da599 100644 (file)
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -50285,7 +50285,8 @@ X86TargetLowering::getRegForInlineAsmConstraint(const TargetRegisterInfo *TRI,
       return std::make_pair(X86::EFLAGS, &X86::CCRRegClass);
 
     // dirflag -> DF
-    if (StringRef("{dirflag}").equals_lower(Constraint))
+    // Only allow for clobber.
+    if (StringRef("{dirflag}").equals_lower(Constraint) && VT == MVT::Other)
       return std::make_pair(X86::DF, &X86::DFCCRRegClass);
 
     // fpsr -> FPSW