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[InstCombine] Add test to track BPI when condition was inverted #86469

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Merged
merged 3 commits into from
Apr 19, 2024
Merged

[InstCombine] Add test to track BPI when condition was inverted #86469

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[InstCombine] Add test to track BPI when condition was inverted
HaohaiWen Mar 25, 2024
075a2ae
Merge remote-tracking branch 'origin/main' into instcombine-test
HaohaiWen Apr 18, 2024
2ce8376
Rename test
HaohaiWen Apr 18, 2024
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36 changes: 36 additions & 0 deletions llvm/test/Transforms/InstCombine/abandon-bpi.ll
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; RUN: opt < %s -passes="print<branch-prob>,instcombine,print<branch-prob>" -S 2>&1 | FileCheck %s

; CHECK: Printing analysis 'Branch Probability Analysis' for function 'invert_cond':
; CHECK-NEXT: ---- Branch Probabilities ----
; CHECK-NEXT: edge %entry -> %bb1 probability is 0x06186186 / 0x80000000 = 4.76%
; CHECK-NEXT: edge %entry -> %bb2 probability is 0x79e79e7a / 0x80000000 = 95.24% [HOT edge]
; CHECK-NEXT: Printing analysis 'Branch Probability Analysis' for function 'invert_cond':
; CHECK-NEXT: ---- Branch Probabilities ----
; CHECK-NEXT: edge %entry -> %bb2 probability is 0x06186186 / 0x80000000 = 4.76%
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bb2 probability is obvious wrong after instcombine in this case

; CHECK-NEXT: edge %entry -> %bb1 probability is 0x79e79e7a / 0x80000000 = 95.24% [HOT edge]

define i32 @invert_cond(ptr %p) {
; CHECK-LABEL: define i32 @invert_cond(
; CHECK-SAME: ptr [[P:%.*]]) {
; CHECK-NEXT: entry:
; CHECK-NEXT: [[COND_NOT:%.*]] = icmp eq ptr [[P]], null
; CHECK-NEXT: br i1 [[COND_NOT]], label [[BB2:%.*]], label [[BB1:%.*]], !prof [[PROF0:![0-9]+]]
; CHECK: bb1:
; CHECK-NEXT: ret i32 0
; CHECK: bb2:
; CHECK-NEXT: ret i32 1
;
entry:
%cond = icmp ne ptr %p, null
br i1 %cond, label %bb1, label %bb2, !prof !1

bb1:
ret i32 0;

bb2:
ret i32 1;
}

!1 = !{!"branch_weights", i32 1, i32 20}
; CHECK: [[PROF0]] = !{!"branch_weights", i32 20, i32 1}