diff options
| -rw-r--r-- | llvm/lib/Analysis/ValueTracking.cpp | 1 | ||||
| -rw-r--r-- | llvm/test/Transforms/LICM/hoisting.ll | 27 |
2 files changed, 28 insertions, 0 deletions
diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp index 073b4e6ab26..d31472c0d33 100644 --- a/llvm/lib/Analysis/ValueTracking.cpp +++ b/llvm/lib/Analysis/ValueTracking.cpp @@ -3257,6 +3257,7 @@ bool llvm::isSafeToSpeculativelyExecute(const Value *V, case Intrinsic::dbg_value: return true; + case Intrinsic::bitreverse: case Intrinsic::bswap: case Intrinsic::ctlz: case Intrinsic::ctpop: diff --git a/llvm/test/Transforms/LICM/hoisting.ll b/llvm/test/Transforms/LICM/hoisting.ll index cb6981ede1e..c61131b476b 100644 --- a/llvm/test/Transforms/LICM/hoisting.ll +++ b/llvm/test/Transforms/LICM/hoisting.ll @@ -5,6 +5,8 @@ declare void @foo() +declare i32 @llvm.bitreverse.i32(i32) + ; This testcase tests for a problem where LICM hoists ; potentially trapping instructions when they are not guaranteed to execute. define i32 @test1(i1 %c) { @@ -122,3 +124,28 @@ then: ; preds = %tailrecurse ifend: ; preds = %tailrecurse ret { i32*, i32 } %d } + +; CHECK: define i32 @hoist_bitreverse(i32) +; CHECK: bitreverse +; CHECK: br label %header +define i32 @hoist_bitreverse(i32) { + br label %header + +header: + %sum = phi i32 [ 0, %1 ], [ %5, %latch ] + %2 = phi i32 [ 0, %1 ], [ %6, %latch ] + %3 = icmp slt i32 %2, 1024 + br i1 %3, label %body, label %return + +body: + %4 = call i32 @llvm.bitreverse.i32(i32 %0) + %5 = add i32 %sum, %4 + br label %latch + +latch: + %6 = add nsw i32 %2, 1 + br label %header + +return: + ret i32 %sum +} |
