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| author | Duncan P. N. Exon Smith <dexonsmith@apple.com> | 2014-08-16 01:54:32 +0000 |
|---|---|---|
| committer | Duncan P. N. Exon Smith <dexonsmith@apple.com> | 2014-08-16 01:54:32 +0000 |
| commit | 0c39d40c8b1e3ef028b4082593896e24633a66d7 (patch) | |
| tree | b70be8489bdd6a050bc50bc3497cf9f585fa3e48 | |
| parent | 1b44db22c6e378080539a35ce1fd1f9b1f85c9b1 (diff) | |
| download | bcm5719-llvm-0c39d40c8b1e3ef028b4082593896e24633a66d7.tar.gz bcm5719-llvm-0c39d40c8b1e3ef028b4082593896e24633a66d7.zip | |
IR: Don't add inbounds to GEPs of extern_weak variables
Global variables that have `extern_weak` linkage may be null, so it's
incorrect to add `inbounds` when constant folding.
This also fixes a bug when parsing global aliases, whose forward
reference placeholders are global variables with `extern_weak` linkage.
If GEPs to these aliases are encountered before the alias itself, the
GEPs would incorrectly gain the `inbounds` keyword as well.
llvm-svn: 215803
| -rw-r--r-- | llvm/lib/IR/ConstantFold.cpp | 7 | ||||
| -rw-r--r-- | llvm/test/Assembler/ConstantExprNoFold.ll | 12 |
2 files changed, 16 insertions, 3 deletions
diff --git a/llvm/lib/IR/ConstantFold.cpp b/llvm/lib/IR/ConstantFold.cpp index 395ac3907ba..9124c111935 100644 --- a/llvm/lib/IR/ConstantFold.cpp +++ b/llvm/lib/IR/ConstantFold.cpp @@ -2144,9 +2144,10 @@ static Constant *ConstantFoldGetElementPtrImpl(Constant *C, // If all indices are known integers and normalized, we can do a simple // check for the "inbounds" property. - if (!Unknown && !inBounds && - isa<GlobalVariable>(C) && isInBoundsIndices(Idxs)) - return ConstantExpr::getInBoundsGetElementPtr(C, Idxs); + if (!Unknown && !inBounds) + if (auto *GV = dyn_cast<GlobalVariable>(C)) + if (!GV->hasExternalWeakLinkage() && isInBoundsIndices(Idxs)) + return ConstantExpr::getInBoundsGetElementPtr(C, Idxs); return nullptr; } diff --git a/llvm/test/Assembler/ConstantExprNoFold.ll b/llvm/test/Assembler/ConstantExprNoFold.ll index d21441372bf..04ad3f5b130 100644 --- a/llvm/test/Assembler/ConstantExprNoFold.ll +++ b/llvm/test/Assembler/ConstantExprNoFold.ll @@ -25,3 +25,15 @@ target datalayout = "p:32:32" ; CHECK: @E = global i64 addrspace(1)* addrspacecast (i64* @A to i64 addrspace(1)*) @E = global i64 addrspace(1)* addrspacecast(i64* @A to i64 addrspace(1)*) + +; Don't add an inbounds on @weak.gep, since @weak may be null. +; CHECK: @weak.gep = global i32* getelementptr (i32* @weak, i32 1) +@weak.gep = global i32* getelementptr (i32* @weak, i32 1) +@weak = extern_weak global i32 + +; Don't add an inbounds on @glob.a3, since it's not inbounds. +; CHECK: @glob.a3 = alias getelementptr (i32* @glob.a2, i32 1) +@glob = global i32 0 +@glob.a3 = alias getelementptr (i32* @glob.a2, i32 1) +@glob.a2 = alias getelementptr (i32* @glob.a1, i32 1) +@glob.a1 = alias i32* @glob |
