diff options
| author | Hal Finkel <hfinkel@anl.gov> | 2016-07-11 03:08:49 +0000 |
|---|---|---|
| committer | Hal Finkel <hfinkel@anl.gov> | 2016-07-11 03:08:49 +0000 |
| commit | 0017f3683d7bcf83f7af2791dc3b2d9fbeaacbd9 (patch) | |
| tree | ff0241acd407bdc184a35c3d17beb993716f2633 | |
| parent | 837551f8d61cbdbe2de999b295f2d48c4d0db02e (diff) | |
Teach isDereferenceablePointer to look through returned-argument functions
For functions which are known to return their argument,
isDereferenceableAndAlignedPointer can examine the argument value.
Differential Revision: http://reviews.llvm.org/D9384
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@275038 91177308-0d34-0410-b5e6-96231b3b80d8
| -rw-r--r-- | lib/Analysis/Loads.cpp | 5 | ||||
| -rw-r--r-- | test/Analysis/ValueTracking/memory-dereferenceable.ll | 5 |
2 files changed, 9 insertions, 1 deletions
diff --git a/lib/Analysis/Loads.cpp b/lib/Analysis/Loads.cpp index 309a1d95efb..75426b54195 100644 --- a/lib/Analysis/Loads.cpp +++ b/lib/Analysis/Loads.cpp @@ -101,6 +101,11 @@ static bool isDereferenceableAndAlignedPointer( return isDereferenceableAndAlignedPointer(ASC->getOperand(0), Align, Size, DL, CtxI, DT, Visited); + if (auto CS = ImmutableCallSite(V)) + if (const Value *RV = CS.getReturnedArgOperand()) + return isDereferenceableAndAlignedPointer(RV, Align, Size, DL, CtxI, DT, + Visited); + // If we don't know, assume the worst. return false; } diff --git a/test/Analysis/ValueTracking/memory-dereferenceable.ll b/test/Analysis/ValueTracking/memory-dereferenceable.ll index 15a93328974..29c31b95b18 100644 --- a/test/Analysis/ValueTracking/memory-dereferenceable.ll +++ b/test/Analysis/ValueTracking/memory-dereferenceable.ll @@ -43,7 +43,8 @@ entry: %load4 = load i32, i32 addrspace(1)* %relocate ; CHECK-NOT: %nparam - %nparam = getelementptr i32, i32 addrspace(1)* %dparam, i32 5 + %dpa = call i32 addrspace(1)* @func1(i32 addrspace(1)* %dparam) + %nparam = getelementptr i32, i32 addrspace(1)* %dpa, i32 5 %load5 = load i32, i32 addrspace(1)* %nparam ; Load from a non-dereferenceable load @@ -162,6 +163,8 @@ if.end: declare token @llvm.experimental.gc.statepoint.p0f_i1f(i64, i32, i1 ()*, i32, i32, ...) declare i32 addrspace(1)* @llvm.experimental.gc.relocate.p1i32(token, i32, i32) +declare i32 addrspace(1)* @func1(i32 addrspace(1)* returned) nounwind argmemonly + !0 = !{i64 4} !1 = !{i64 2} !2 = !{} |