diff options
| -rw-r--r-- | llvm/lib/CodeGen/CodeGenPrepare.cpp | 1 | ||||
| -rw-r--r-- | llvm/test/CodeGen/X86/cmov-into-branch.ll | 25 |
2 files changed, 26 insertions, 0 deletions
diff --git a/llvm/lib/CodeGen/CodeGenPrepare.cpp b/llvm/lib/CodeGen/CodeGenPrepare.cpp index f05afd05874..003db39fe5f 100644 --- a/llvm/lib/CodeGen/CodeGenPrepare.cpp +++ b/llvm/lib/CodeGen/CodeGenPrepare.cpp @@ -6122,6 +6122,7 @@ bool CodeGenPrepare::optimizeSelectInst(SelectInst *SI) { BasicBlock *StartBlock = SI->getParent(); BasicBlock::iterator SplitPt = ++(BasicBlock::iterator(LastSI)); BasicBlock *EndBlock = StartBlock->splitBasicBlock(SplitPt, "select.end"); + BFI->setBlockFreq(EndBlock, BFI->getBlockFreq(StartBlock).getFrequency()); // Delete the unconditional branch that was just created by the split. StartBlock->getTerminator()->eraseFromParent(); diff --git a/llvm/test/CodeGen/X86/cmov-into-branch.ll b/llvm/test/CodeGen/X86/cmov-into-branch.ll index 6cc81ac0833..d9ab2550f79 100644 --- a/llvm/test/CodeGen/X86/cmov-into-branch.ll +++ b/llvm/test/CodeGen/X86/cmov-into-branch.ll @@ -165,6 +165,30 @@ define i32 @weighted_select_pgso(i32 %a, i32 %b) !prof !14 { ret i32 %sel } +; If two selects in a row are predictable, turn them into branches. +define i32 @weighted_selects(i32 %a, i32 %b) !prof !19 { +; CHECK-LABEL: weighted_selects: +; CHECK: # %bb.0: +; CHECK-NEXT: movl %esi, %eax +; CHECK-NEXT: testl %edi, %edi +; CHECK-NEXT: movl %edi, %ecx +; CHECK-NEXT: jne .LBB11_2 +; CHECK-NEXT: # %bb.1: # %select.false +; CHECK-NEXT: movl %eax, %ecx +; CHECK-NEXT: .LBB11_2: # %select.end +; CHECK-NEXT: testl %ecx, %ecx +; CHECK-NEXT: jne .LBB11_4 +; CHECK-NEXT: # %bb.3: # %select.false2 +; CHECK-NEXT: movl %edi, %eax +; CHECK-NEXT: .LBB11_4: # %select.end1 +; CHECK-NEXT: retq + %cmp = icmp ne i32 %a, 0 + %sel = select i1 %cmp, i32 %a, i32 %b, !prof !16 + %cmp1 = icmp ne i32 %sel, 0 + %sel1 = select i1 %cmp1, i32 %b, i32 %a, !prof !16 + ret i32 %sel1 +} + !llvm.module.flags = !{!0} !0 = !{i32 1, !"ProfileSummary", !1} !1 = !{!2, !3, !4, !5, !6, !7, !8, !9} @@ -185,3 +209,4 @@ define i32 @weighted_select_pgso(i32 %a, i32 %b) !prof !14 { !16 = !{!"branch_weights", i32 1, i32 100} !17 = !{!"branch_weights", i32 100, i32 1} !18 = !{!"branch_weights", i32 0, i32 0} +!19 = !{!"function_entry_count", i64 100} |
