diff options
Diffstat (limited to 'llvm/test/Transforms')
| -rw-r--r-- | llvm/test/Transforms/SimplifyCFG/speculate-math.ll | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/llvm/test/Transforms/SimplifyCFG/speculate-math.ll b/llvm/test/Transforms/SimplifyCFG/speculate-math.ll index 0ba93d29117..442e8677e97 100644 --- a/llvm/test/Transforms/SimplifyCFG/speculate-math.ll +++ b/llvm/test/Transforms/SimplifyCFG/speculate-math.ll @@ -7,6 +7,33 @@ declare float @llvm.fabs.f32(float) nounwind readonly declare float @llvm.minnum.f32(float, float) nounwind readonly declare float @llvm.maxnum.f32(float, float) nounwind readonly +; FIXME: This is intended to be a temporary test. As discussed in +; D12882, we actually do want to speculate even expensive operations +; in SimplifyCFG because it can expose more optimizations for other +; passes. Therefore, we either need to adjust SimplifyCFG's +; calculations that use the TTI cost model or use a different cost +; model for deciding which ops should be speculated in SimplifyCFG. +; We should also be using the TTI cost model later - for example in +; CodeGenPrepare - to potentially undo this speculation. + +; Do not speculate fdiv by default because it is generally expensive. + +; CHECK-LABEL: @fdiv_test( +; CHECK-NOT: select +define double @fdiv_test(double %a, double %b) { +entry: + %cmp = fcmp ogt double %a, 0.0 + br i1 %cmp, label %cond.true, label %cond.end + +cond.true: + %div = fdiv double %b, %a + br label %cond.end + +cond.end: + %cond = phi double [ %div, %cond.true ], [ 0.0, %entry ] + ret double %cond +} + ; CHECK-LABEL: @sqrt_test( ; CHECK: select define void @sqrt_test(float addrspace(1)* noalias nocapture %out, float %a) nounwind { |
