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| author | Chris Lattner <sabre@nondot.org> | 2008-01-31 04:12:50 +0000 |
|---|---|---|
| committer | Chris Lattner <sabre@nondot.org> | 2008-01-31 04:12:50 +0000 |
| commit | 6860f3cef7d5ed22cf7626e357c202124c43c899 (patch) | |
| tree | 260cc274407e56a365b53fd0eb031db5cfd7b8d8 | |
| parent | 64924859b6b09d1cfb62fecf5954ec6c27cb58fe (diff) | |
Fix PR1921 by promoting negative indices to intptrty.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@46599 91177308-0d34-0410-b5e6-96231b3b80d8
| -rw-r--r-- | CodeGen/CGExprScalar.cpp | 16 | ||||
| -rw-r--r-- | test/CodeGen/exprs.c | 6 |
2 files changed, 20 insertions, 2 deletions
diff --git a/CodeGen/CGExprScalar.cpp b/CodeGen/CGExprScalar.cpp index e7f58bb468..820234033b 100644 --- a/CodeGen/CGExprScalar.cpp +++ b/CodeGen/CGExprScalar.cpp @@ -767,8 +767,20 @@ Value *ScalarExprEmitter::EmitSub(const BinOpInfo &Ops) { assert(!isa<llvm::PointerType>(Ops.RHS->getType()) && "ptr-ptr shouldn't get here"); // FIXME: The pointer could point to a VLA. - Value *NegatedRHS = Builder.CreateNeg(Ops.RHS, "sub.ptr.neg"); - return Builder.CreateGEP(Ops.LHS, NegatedRHS, "sub.ptr"); + Value *Idx = Builder.CreateNeg(Ops.RHS, "sub.ptr.neg"); + + unsigned Width = cast<llvm::IntegerType>(Idx->getType())->getBitWidth(); + if (Width < CGF.LLVMPointerWidth) { + // Zero or sign extend the pointer value based on whether the index is + // signed or not. + const llvm::Type *IdxType = llvm::IntegerType::get(CGF.LLVMPointerWidth); + if (Ops.E->getRHS()->getType().getCanonicalType()->isSignedIntegerType()) + Idx = Builder.CreateSExt(Idx, IdxType, "idx.ext"); + else + Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext"); + } + + return Builder.CreateGEP(Ops.LHS, Idx, "sub.ptr"); } Value *ScalarExprEmitter::VisitBinSub(const BinaryOperator *E) { diff --git a/test/CodeGen/exprs.c b/test/CodeGen/exprs.c index 9115369173..16b63f8883 100644 --- a/test/CodeGen/exprs.c +++ b/test/CodeGen/exprs.c @@ -17,3 +17,9 @@ void *test(int *i) { _Bool test2b; int test2() {if (test2b);} +// PR1921 +int test3() { + const unsigned char *bp; + bp -= (short)1; +} + |