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| author | Eli Friedman <eli.friedman@gmail.com> | 2011-08-16 01:28:22 +0000 |
|---|---|---|
| committer | Eli Friedman <eli.friedman@gmail.com> | 2011-08-16 01:28:22 +0000 |
| commit | 2199dfb0e6b98fdce0a3c863eb84d466d426b968 (patch) | |
| tree | 1a0d73151aaa4e9664155657b3e833f123a89748 | |
| parent | 89a01a0cbd86979b62a3570547c2c7308a3741c7 (diff) | |
Revert a bit of r137667; the logic in question can safely handle atomic load/store.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137702 91177308-0d34-0410-b5e6-96231b3b80d8
| -rw-r--r-- | lib/Transforms/IPO/FunctionAttrs.cpp | 8 | ||||
| -rw-r--r-- | test/Transforms/FunctionAttrs/atomic.ll | 21 |
2 files changed, 25 insertions, 4 deletions
diff --git a/lib/Transforms/IPO/FunctionAttrs.cpp b/lib/Transforms/IPO/FunctionAttrs.cpp index c43f4b9870..0edf342750 100644 --- a/lib/Transforms/IPO/FunctionAttrs.cpp +++ b/lib/Transforms/IPO/FunctionAttrs.cpp @@ -163,15 +163,15 @@ bool FunctionAttrs::AddReadAttrs(const CallGraphSCC &SCC) { ReadsMemory = true; continue; } else if (LoadInst *LI = dyn_cast<LoadInst>(I)) { - // Ignore non-volatile loads from local memory. - if (LI->isUnordered()) { + // Ignore non-volatile loads from local memory. (Atomic is okay here.) + if (!LI->isVolatile()) { AliasAnalysis::Location Loc = AA->getLocation(LI); if (AA->pointsToConstantMemory(Loc, /*OrLocal=*/true)) continue; } } else if (StoreInst *SI = dyn_cast<StoreInst>(I)) { - // Ignore non-volatile stores to local memory. - if (SI->isUnordered()) { + // Ignore non-volatile stores to local memory. (Atomic is okay here.) + if (!SI->isVolatile()) { AliasAnalysis::Location Loc = AA->getLocation(SI); if (AA->pointsToConstantMemory(Loc, /*OrLocal=*/true)) continue; diff --git a/test/Transforms/FunctionAttrs/atomic.ll b/test/Transforms/FunctionAttrs/atomic.ll new file mode 100644 index 0000000000..62f8fa5a1d --- /dev/null +++ b/test/Transforms/FunctionAttrs/atomic.ll @@ -0,0 +1,21 @@ +; RUN: opt -basicaa -functionattrs -S < %s | FileCheck %s + +; Atomic load/store to local doesn't affect whether a function is +; readnone/readonly. +define i32 @test1(i32 %x) uwtable ssp { +; CHECK: define i32 @test1(i32 %x) uwtable readnone ssp { +entry: + %x.addr = alloca i32, align 4 + store atomic i32 %x, i32* %x.addr seq_cst, align 4 + %r = load atomic i32* %x.addr seq_cst, align 4 + ret i32 %r +} + +; A function with an Acquire load is not readonly. +define i32 @test2(i32* %x) uwtable ssp { +; CHECK: define i32 @test2(i32 %x) uwtable ssp { +entry: + %r = load atomic i32* %x seq_cst, align 4 + ret i32 %r +} + |