Fix the CBE's handling of instructions whose result is an i1. Previously,
we did not truncate the value down to i1 with (x&1). This caused a problem
when the computation of x was nontrivial, for example, "add i1 1, 1" would
return 2 instead of 0.
This makes the testcase compile into:
...
llvm_cbe_t = (((llvm_cbe_r == 0u) + (llvm_cbe_r == 0u))&1);
llvm_cbe_u = (((unsigned int )(bool )llvm_cbe_t));
...
instead of:
...
llvm_cbe_t = ((llvm_cbe_r == 0u) + (llvm_cbe_r == 0u));
llvm_cbe_u = (((unsigned int )(bool )llvm_cbe_t));
...
This fixes a miscompilation of mediabench/adpcm/rawdaudio/rawdaudio and
403.gcc with the CBE, regressions from LLVM 2.2. Tanya, please pull
this into the release branch.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51813 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/CBackend/CBackend.cpp b/lib/Target/CBackend/CBackend.cpp
index 2ace6eb..440ce1c 100644
--- a/lib/Target/CBackend/CBackend.cpp
+++ b/lib/Target/CBackend/CBackend.cpp
@@ -155,6 +155,7 @@
void writeOperand(Value *Operand);
void writeOperandRaw(Value *Operand);
+ void writeInstComputationInline(Instruction &I);
void writeOperandInternal(Value *Operand);
void writeOperandWithCast(Value* Operand, unsigned Opcode);
void writeOperandWithCast(Value* Operand, const ICmpInst &I);
@@ -1217,12 +1218,32 @@
return Name;
}
+/// writeInstComputationInline - Emit the computation for the specified
+/// instruction inline, with no destination provided.
+void CWriter::writeInstComputationInline(Instruction &I) {
+ // If this is a non-trivial bool computation, make sure to truncate down to
+ // a 1 bit value. This is important because we want "add i1 x, y" to return
+ // "0" when x and y are true, not "2" for example.
+ bool NeedBoolTrunc = false;
+ if (I.getType() == Type::Int1Ty && !isa<ICmpInst>(I) && !isa<FCmpInst>(I))
+ NeedBoolTrunc = true;
+
+ if (NeedBoolTrunc)
+ Out << "((";
+
+ visit(I);
+
+ if (NeedBoolTrunc)
+ Out << ")&1)";
+}
+
+
void CWriter::writeOperandInternal(Value *Operand) {
if (Instruction *I = dyn_cast<Instruction>(Operand))
+ // Should we inline this instruction to build a tree?
if (isInlinableInst(*I) && !isDirectAlloca(I)) {
- // Should we inline this instruction to build a tree?
Out << '(';
- visit(*I);
+ writeInstComputationInline(*I);
Out << ')';
return;
}
@@ -2152,12 +2173,12 @@
outputLValue(II);
else
Out << " ";
- visit(*II);
+ writeInstComputationInline(*II);
Out << ";\n";
}
}
- // Don't emit prefix or suffix for the terminator...
+ // Don't emit prefix or suffix for the terminator.
visit(*BB->getTerminator());
}
@@ -2481,29 +2502,34 @@
void CWriter::visitCastInst(CastInst &I) {
const Type *DstTy = I.getType();
const Type *SrcTy = I.getOperand(0)->getType();
- Out << '(';
if (isFPIntBitCast(I)) {
+ Out << '(';
// These int<->float and long<->double casts need to be handled specially
Out << GetValueName(&I) << "__BITCAST_TEMPORARY."
<< getFloatBitCastField(I.getOperand(0)->getType()) << " = ";
writeOperand(I.getOperand(0));
Out << ", " << GetValueName(&I) << "__BITCAST_TEMPORARY."
<< getFloatBitCastField(I.getType());
- } else {
- printCast(I.getOpcode(), SrcTy, DstTy);
- if (I.getOpcode() == Instruction::SExt && SrcTy == Type::Int1Ty) {
- // Make sure we really get a sext from bool by subtracing the bool from 0
- Out << "0-";
- }
- writeOperand(I.getOperand(0));
- if (DstTy == Type::Int1Ty &&
- (I.getOpcode() == Instruction::Trunc ||
- I.getOpcode() == Instruction::FPToUI ||
- I.getOpcode() == Instruction::FPToSI ||
- I.getOpcode() == Instruction::PtrToInt)) {
- // Make sure we really get a trunc to bool by anding the operand with 1
- Out << "&1u";
- }
+ Out << ')';
+ return;
+ }
+
+ Out << '(';
+ printCast(I.getOpcode(), SrcTy, DstTy);
+
+ // Make a sext from i1 work by subtracting the i1 from 0 (an int).
+ if (SrcTy == Type::Int1Ty && I.getOpcode() == Instruction::SExt)
+ Out << "0-";
+
+ writeOperand(I.getOperand(0));
+
+ if (DstTy == Type::Int1Ty &&
+ (I.getOpcode() == Instruction::Trunc ||
+ I.getOpcode() == Instruction::FPToUI ||
+ I.getOpcode() == Instruction::FPToSI ||
+ I.getOpcode() == Instruction::PtrToInt)) {
+ // Make sure we really get a trunc to bool by anding the operand with 1
+ Out << "&1u";
}
Out << ')';
}