[llvm] [InstCombine] Preserve profile data with select instructions and binary operators (PR #158375)

[Alan Zhao via llvm-commits]

================
@@ -0,0 +1,39 @@
+; RUN: opt < %s -passes=instcombine -S | FileCheck %s
----------------
alanzhao1 wrote:

Tried that, didn't work:

```ll
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --check-globals all --version 6
; RUN: opt < %s -passes=instcombine -S | FileCheck %s

define i32 @LHSBin(i1 %C) !prof !0 {
; CHECK-LABEL: define i32 @LHSBin(
; CHECK-SAME: i1 [[C:%.*]]) !prof [[PROF0:![0-9]+]] {
; CHECK-NEXT:    [[V:%.*]] = select i1 [[C]], i32 1010, i32 20
; CHECK-NEXT:    ret i32 [[V]]
;
  %A = select i1 %C, i32 1000, i32 10, !prof !1
  %V = add i32 %A, 10
  ret i32 %V
}

define i32 @RHSBin(i1 %C) !prof !0 {
; CHECK-LABEL: define i32 @RHSBin(
; CHECK-SAME: i1 [[C:%.*]]) !prof [[PROF0]] {
; CHECK-NEXT:    [[V:%.*]] = select i1 [[C]], i32 1010, i32 20
; CHECK-NEXT:    ret i32 [[V]]
;
  %A = select i1 %C, i32 1000, i32 10, !prof !1
  %V = add i32 10, %A
  ret i32 %V;
}

define i32 @BothBin(i1 %C) !prof !0 {
; CHECK-LABEL: define i32 @BothBin(
; CHECK-SAME: i1 [[C:%.*]]) !prof [[PROF0]] {
; CHECK-NEXT:    [[V:%.*]] = select i1 [[C]], i32 2000, i32 20
; CHECK-NEXT:    ret i32 [[V]]
;
  %A = select i1 %C, i32 1000, i32 10, !prof !1
  %B = select i1 %C, i32 1000, i32 10, !prof !1
  %V = add i32 %A, %B
  ret i32 %V;
}

define i32 @NegBin(i1 %C) !prof !0 {
; CHECK-LABEL: define i32 @NegBin(
; CHECK-SAME: i1 [[C:%.*]]) !prof [[PROF0]] {
; CHECK-NEXT:    [[V:%.*]] = select i1 [[C]], i32 1010, i32 0
; CHECK-NEXT:    ret i32 [[V]]
;
  %A = select i1 %C, i32 1000, i32 -10, !prof !1
  %V = add i32 %A, 10
  ret i32 %V
}

!0 = !{!"function_entry_count", i64 1000}
!1 = !{!"branch_weights", i32 2, i32 3}
;.
; CHECK: [[PROF0]] = !{!"function_entry_count", i64 1000}
;.
```

https://github.com/llvm/llvm-project/pull/158375