diff options
| -rw-r--r-- | llvm/test/CodeGen/X86/cmov-into-branch.ll | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/llvm/test/CodeGen/X86/cmov-into-branch.ll b/llvm/test/CodeGen/X86/cmov-into-branch.ll index 8830357d54d..99aa4d51429 100644 --- a/llvm/test/CodeGen/X86/cmov-into-branch.ll +++ b/llvm/test/CodeGen/X86/cmov-into-branch.ll @@ -64,3 +64,35 @@ define i32 @test5(i32 %a, i32* nocapture %b, i32 %x, i32 %y) { %cond5 = select i1 %cmp, i32 %cond, i32 %x ret i32 %cond5 } + +; If a select is not obviously predictable, don't turn it into a branch. +define i32 @weighted_select1(i32 %a, i32 %b) { +; CHECK-LABEL: weighted_select1: +; CHECK: # BB#0: +; CHECK-NEXT: testl %edi, %edi +; CHECK-NEXT: cmovnel %edi, %esi +; CHECK-NEXT: movl %esi, %eax +; CHECK-NEXT: retq +; + %cmp = icmp ne i32 %a, 0 + %sel = select i1 %cmp, i32 %a, i32 %b, !prof !0 + ret i32 %sel +} + +; TODO: If a select is obviously predictable, turn it into a branch. +define i32 @weighted_select2(i32 %a, i32 %b) { +; CHECK-LABEL: weighted_select2: +; CHECK: # BB#0: +; CHECK-NEXT: testl %edi, %edi +; CHECK-NEXT: cmovnel %edi, %esi +; CHECK-NEXT: movl %esi, %eax +; CHECK-NEXT: retq +; + %cmp = icmp ne i32 %a, 0 + %sel = select i1 %cmp, i32 %a, i32 %b, !prof !1 + ret i32 %sel +} + +!0 = !{!"branch_weights", i32 1, i32 99} +!1 = !{!"branch_weights", i32 1, i32 100} + |
