test/Transforms/InstCombine/strrchr-3.ll

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; Verify the strrchr("", c) to (unsigned char)c ? "" : 0 transformetion.
;
; RUN: opt < %s -passes=instcombine -S | FileCheck %s

@s10 = constant [11 x i8] c"0123456789\00"

declare i8* @strrchr(i8*, i32)

; Fold strrchr(s + 10, c) to (unsigned char)c ? 0 : s + 10.

define i8* @fold_strrchr_sp10_x(i32 %c) {
; CHECK-LABEL: @fold_strrchr_sp10_x(
; CHECK-NEXT:    [[TMP1:%.*]] = trunc i32 [[C:%.*]] to i8
; CHECK-NEXT:    [[MEMRCHR_CHAR0CMP:%.*]] = icmp eq i8 [[TMP1]], 0
; CHECK-NEXT:    [[MEMRCHR_SEL:%.*]] = select i1 [[MEMRCHR_CHAR0CMP]], i8* getelementptr inbounds ([11 x i8], [11 x i8]* @s10, i64 0, i64 10), i8* null
; CHECK-NEXT:    ret i8* [[MEMRCHR_SEL]]
;
  %psp10 = getelementptr [11 x i8], [11 x i8]* @s10, i32 0, i32 10
  %pc = call i8* @strrchr(i8* %psp10, i32 %c)
  ret i8* %pc
}


; Transform strrchr(s + 9, c) to [the equivalent of] memrchr(s + 9, c, 2).

define i8* @call_strrchr_sp9_x(i32 %c) {
; CHECK-LABEL: @call_strrchr_sp9_x(
; CHECK-NEXT:    [[MEMRCHR:%.*]] = call i8* @memrchr(i8* noundef nonnull dereferenceable(2) getelementptr inbounds ([11 x i8], [11 x i8]* @s10, i64 0, i64 9), i32 [[C:%.*]], i64 2)
; CHECK-NEXT:    ret i8* [[MEMRCHR]]
;
  %psp9 = getelementptr [11 x i8], [11 x i8]* @s10, i32 0, i32 9
  %pc = call i8* @strrchr(i8* %psp9, i32 %c)
  ret i8* %pc
}


; Do not transform strrchr(s + 2, c) (for short strings this could be
; folded into a chain of OR expressions ala D128011).

define i8* @call_strrchr_sp2_x(i32 %c) {
; CHECK-LABEL: @call_strrchr_sp2_x(
; CHECK-NEXT:    [[MEMRCHR:%.*]] = call i8* @memrchr(i8* noundef nonnull dereferenceable(9) getelementptr inbounds ([11 x i8], [11 x i8]* @s10, i64 0, i64 2), i32 [[C:%.*]], i64 9)
; CHECK-NEXT:    ret i8* [[MEMRCHR]]
;
  %psp2 = getelementptr [11 x i8], [11 x i8]* @s10, i32 0, i32 2
  %pc = call i8* @strrchr(i8* %psp2, i32 %c)
  ret i8* %pc
}


; Do not transform strrchr(s + 1, c).

define i8* @call_strrchr_sp1_x(i32 %c) {
; CHECK-LABEL: @call_strrchr_sp1_x(
; CHECK-NEXT:    [[MEMRCHR:%.*]] = call i8* @memrchr(i8* noundef nonnull dereferenceable(10) getelementptr inbounds ([11 x i8], [11 x i8]* @s10, i64 0, i64 1), i32 [[C:%.*]], i64 10)
; CHECK-NEXT:    ret i8* [[MEMRCHR]]
;
  %psp1 = getelementptr [11 x i8], [11 x i8]* @s10, i32 0, i32 1
  %pc = call i8* @strrchr(i8* %psp1, i32 %c)
  ret i8* %pc
}