[llvm] r239897 - [mips] [IAS] Fix LW with relative label operands.

[Toma Tabacu]

Author: tomatabacu
Date: Wed Jun 17 05:43:45 2015
New Revision: 239897

URL: http://llvm.org/viewvc/llvm-project?rev=239897&view=rev
Log:
[mips] [IAS] Fix LW with relative label operands.

Summary:
Previously, MCSymbolRefExpr::create() was called with a StringRef of the symbol
name, which it would then search for in the Symbols StringMap (from MCContext).

However, relative labels (which are temporary symbols) are apparently not stored
in the Symbols StringMap, so we end up creating a new {$,.L}tmp symbol
({$,.L}tmp00, {$,.L}tmp10 etc.) each time we create an MCSymbolRefExpr by
passing in the symbol name as a StringRef.

Fortunately, there is a version of MCSymbolRefExpr::create() which takes an
MCSymbol* and we already have an MCSymbol* at that point, so we can just pass
that in instead of the StringRef.

I also removed the local StringRef calls to MCSymbolRefExpr::create() from
expandMemInst(), as those cases can be handled by evaluateRelocExpr() anyway.

Reviewers: dsanders

Reviewed By: dsanders

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D9938

Modified:
    llvm/trunk/lib/Target/Mips/AsmParser/MipsAsmParser.cpp
    llvm/trunk/test/MC/Mips/mips-expansions.s

Modified: llvm/trunk/lib/Target/Mips/AsmParser/MipsAsmParser.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/Mips/AsmParser/MipsAsmParser.cpp?rev=239897&r1=239896&r2=239897&view=diff
==============================================================================
--- llvm/trunk/lib/Target/Mips/AsmParser/MipsAsmParser.cpp (original)
+++ llvm/trunk/lib/Target/Mips/AsmParser/MipsAsmParser.cpp Wed Jun 17 05:43:45 2015
@@ -2105,7 +2105,6 @@ bool MipsAsmParser::expandBranchImm(MCIn
 void MipsAsmParser::expandMemInst(MCInst &Inst, SMLoc IDLoc,
                                   SmallVectorImpl<MCInst> &Instructions,
                                   bool isLoad, bool isImmOpnd) {
-  const MCSymbolRefExpr *SR;
   MCInst TempInst;
   unsigned ImmOffset, HiOffset, LoOffset;
   const MCExpr *ExprOffset;
@@ -2172,16 +2171,8 @@ void MipsAsmParser::expandMemInst(MCInst
   if (isImmOpnd)
     TempInst.addOperand(MCOperand::createImm(HiOffset));
   else {
-    if (ExprOffset->getKind() == MCExpr::SymbolRef) {
-      SR = static_cast<const MCSymbolRefExpr *>(ExprOffset);
-      const MCSymbolRefExpr *HiExpr = MCSymbolRefExpr::create(
-          SR->getSymbol().getName(), MCSymbolRefExpr::VK_Mips_ABS_HI,
-          getContext());
-      TempInst.addOperand(MCOperand::createExpr(HiExpr));
-    } else {
-      const MCExpr *HiExpr = evaluateRelocExpr(ExprOffset, "hi");
-      TempInst.addOperand(MCOperand::createExpr(HiExpr));
-    }
+    const MCExpr *HiExpr = evaluateRelocExpr(ExprOffset, "hi");
+    TempInst.addOperand(MCOperand::createExpr(HiExpr));
   }
   // Add the instruction to the list.
   Instructions.push_back(TempInst);
@@ -2204,15 +2195,8 @@ void MipsAsmParser::expandMemInst(MCInst
   if (isImmOpnd)
     TempInst.addOperand(MCOperand::createImm(LoOffset));
   else {
-    if (ExprOffset->getKind() == MCExpr::SymbolRef) {
-      const MCSymbolRefExpr *LoExpr = MCSymbolRefExpr::create(
-          SR->getSymbol().getName(), MCSymbolRefExpr::VK_Mips_ABS_LO,
-          getContext());
-      TempInst.addOperand(MCOperand::createExpr(LoExpr));
-    } else {
-      const MCExpr *LoExpr = evaluateRelocExpr(ExprOffset, "lo");
-      TempInst.addOperand(MCOperand::createExpr(LoExpr));
-    }
+    const MCExpr *LoExpr = evaluateRelocExpr(ExprOffset, "lo");
+    TempInst.addOperand(MCOperand::createExpr(LoExpr));
   }
   Instructions.push_back(TempInst);
   TempInst.clear();
@@ -2642,7 +2626,7 @@ const MCExpr *MipsAsmParser::evaluateRel
 
   if (const MCSymbolRefExpr *MSRE = dyn_cast<MCSymbolRefExpr>(Expr)) {
     // It's a symbol, create a symbolic expression from the symbol.
-    StringRef Symbol = MSRE->getSymbol().getName();
+    const MCSymbol *Symbol = &MSRE->getSymbol();
     MCSymbolRefExpr::VariantKind VK = getVariantKind(RelocStr);
     Res = MCSymbolRefExpr::create(Symbol, VK, getContext());
     return Res;

Modified: llvm/trunk/test/MC/Mips/mips-expansions.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/Mips/mips-expansions.s?rev=239897&r1=239896&r2=239897&view=diff
==============================================================================
--- llvm/trunk/test/MC/Mips/mips-expansions.s (original)
+++ llvm/trunk/test/MC/Mips/mips-expansions.s Wed Jun 17 05:43:45 2015
@@ -55,6 +55,12 @@
 # CHECK: sw      $10, %lo(symbol)($1)    # encoding: [A,A,0x2a,0xac]
 # CHECK:                                 #   fixup A - offset: 0, value: symbol at ABS_LO, kind: fixup_Mips_LO16
 
+  lw $8, 1f
+# CHECK: lui $8, %hi($tmp0)              # encoding: [A,A,0x08,0x3c]
+# CHECK:                                 #   fixup A - offset: 0, value: ($tmp0)@ABS_HI, kind: fixup_Mips_HI16
+# CHECK: lw  $8, %lo($tmp0)($8)          # encoding: [A,A,0x08,0x8d]
+# CHECK:                                 #   fixup A - offset: 0, value: ($tmp0)@ABS_LO, kind: fixup_Mips_LO16
+
   lw $10, 655483($4)
 # CHECK: lui     $10, 10                 # encoding: [0x0a,0x00,0x0a,0x3c]
 # CHECK: addu    $10, $10, $4            # encoding: [0x21,0x50,0x44,0x01]
@@ -145,3 +151,6 @@
 # CHECK: lui   $1, 1             # encoding: [0x01,0x00,0x01,0x3c]
 # CHECK: beq   $2, $1, 1332      # encoding: [0x4d,0x01,0x41,0x10]
 # CHECK: nop                     # encoding: [0x00,0x00,0x00,0x00]
+
+1:
+  add $4, $4, $4