[llvm] 91b8c1f - [X86] Simplify some code in emitMemModRMByte. NFCI

[Craig Topper via llvm-commits]

Author: Craig Topper
Date: 2020-07-28T10:46:04-07:00
New Revision: 91b8c1fd0f31a548b75acb3de4dbee09847e19e5

URL: https://github.com/llvm/llvm-project/commit/91b8c1fd0f31a548b75acb3de4dbee09847e19e5
DIFF: https://github.com/llvm/llvm-project/commit/91b8c1fd0f31a548b75acb3de4dbee09847e19e5.diff

LOG: [X86] Simplify some code in emitMemModRMByte. NFCI

Added: 
    

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

Removed: 
    


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diff  --git a/llvm/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp b/llvm/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp
index 900b4d78b6f2..25f108991263 100644
--- a/llvm/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp
+++ b/llvm/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp
@@ -605,23 +605,14 @@ void X86MCCodeEmitter::emitMemModRMByte(const MCInst &MI, unsigned Op,
   static const unsigned SSTable[] = {~0U, 0, 1, ~0U, 2, ~0U, ~0U, ~0U, 3};
   unsigned SS = SSTable[Scale.getImm()];
 
-  if (BaseReg == 0) {
-    // Handle the SIB byte for the case where there is no base, see Intel
-    // Manual 2A, table 2-7. The displacement has already been output.
-    unsigned IndexRegNo;
-    if (IndexReg.getReg())
-      IndexRegNo = getX86RegNum(IndexReg);
-    else // Examples: [ESP+1*<noreg>+4] or [scaled idx]+disp32 (MOD=0,BASE=5)
-      IndexRegNo = 4;
-    emitSIBByte(SS, IndexRegNo, 5, OS);
-  } else {
-    unsigned IndexRegNo;
-    if (IndexReg.getReg())
-      IndexRegNo = getX86RegNum(IndexReg);
-    else
-      IndexRegNo = 4; // For example [ESP+1*<noreg>+4]
-    emitSIBByte(SS, IndexRegNo, getX86RegNum(Base), OS);
-  }
+  unsigned IndexRegNo = IndexReg.getReg() ? getX86RegNum(IndexReg) : 4;
+
+  // Handle the SIB byte for the case where there is no base, see Intel
+  // Manual 2A, table 2-7. The displacement has already been output.
+  if (BaseReg == 0)
+    BaseRegNo = 5;
+
+  emitSIBByte(SS, IndexRegNo, BaseRegNo, OS);
 
   // Do we need to output a displacement?
   if (ForceDisp8)