diff options
| -rw-r--r-- | lib/Transforms/Scalar/LoopStrengthReduce.cpp | 13 | ||||
| -rw-r--r-- | test/CodeGen/ARM/commute-movcc.ll | 4 |
2 files changed, 15 insertions, 2 deletions
diff --git a/lib/Transforms/Scalar/LoopStrengthReduce.cpp b/lib/Transforms/Scalar/LoopStrengthReduce.cpp index 7e71683dc1..d57ec22f44 100644 --- a/lib/Transforms/Scalar/LoopStrengthReduce.cpp +++ b/lib/Transforms/Scalar/LoopStrengthReduce.cpp @@ -1282,10 +1282,19 @@ static bool isLegalUse(const TargetLowering::AddrMode &AM, // If we have low-level target information, ask the target if it can fold an // integer immediate on an icmp. if (AM.BaseOffs != 0) { - if (TLI) return TLI->isLegalICmpImmediate(-(uint64_t)AM.BaseOffs); - return false; + if (!TLI) + return false; + // We have one of: + // ICmpZero BaseReg + Offset => ICmp BaseReg, -Offset + // ICmpZero -1*ScaleReg + Offset => ICmp ScaleReg, Offset + // Offs is the ICmp immediate. + int64_t Offs = AM.BaseOffs; + if (AM.Scale == 0) + Offs = -(uint64_t)Offs; // The cast does the right thing with INT64_MIN. + return TLI->isLegalICmpImmediate(Offs); } + // ICmpZero BaseReg + -1*ScaleReg => ICmp BaseReg, ScaleReg return true; case LSRUse::Basic: diff --git a/test/CodeGen/ARM/commute-movcc.ll b/test/CodeGen/ARM/commute-movcc.ll index f53ac17876..7316452cd6 100644 --- a/test/CodeGen/ARM/commute-movcc.ll +++ b/test/CodeGen/ARM/commute-movcc.ll @@ -17,7 +17,11 @@ ; CHECK: movls ; CHECK-NOT: mov +; This is really an LSR test: Make sure that cmp is using the incremented +; induction variable. ; CHECK: %if.end8 +; CHECK: add{{(s|\.w)?}} [[IV:r[0-9]+]], {{.*}}#1 +; CHECK: cmp [[IV]], # define i32 @f(i32* nocapture %a, i32 %Pref) nounwind ssp { entry: |