[llvm] r279923 - [X86] Keep looping over operands looking for byte registers even if we already found a register that requires a REX prefix. Otherwise we don't error if a high byte register is used after SPL/BPL/DIL/SIL.

[Craig Topper via llvm-commits]

Author: ctopper
Date: Sat Aug 27 12:13:41 2016
New Revision: 279923

URL: http://llvm.org/viewvc/llvm-project?rev=279923&view=rev
Log:
[X86] Keep looping over operands looking for byte registers even if we already found a register that requires a REX prefix. Otherwise we don't error if a high byte register is used after SPL/BPL/DIL/SIL.

Modified:
    llvm/trunk/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp

Modified: llvm/trunk/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp?rev=279923&r1=279922&r2=279923&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp (original)
+++ llvm/trunk/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp Sat Aug 27 12:13:41 2016
@@ -1017,11 +1017,10 @@ uint8_t X86MCCodeEmitter::DetermineREXPr
     unsigned Reg = MO.getReg();
     if (Reg == X86::AH || Reg == X86::BH || Reg == X86::CH || Reg == X86::DH)
       UsesHighByteReg = true;
-    if (!X86II::isX86_64NonExtLowByteReg(Reg)) continue;
-    // FIXME: The caller of DetermineREXPrefix slaps this prefix onto anything
-    // that returns non-zero.
-    REX |= 0x40; // REX fixed encoding prefix
-    break;
+    if (X86II::isX86_64NonExtLowByteReg(Reg))
+      // FIXME: The caller of DetermineREXPrefix slaps this prefix onto anything
+      // that returns non-zero.
+      REX |= 0x40; // REX fixed encoding prefix
   }
 
   switch (TSFlags & X86II::FormMask) {