test/Transforms/InstCombine/memchr-6.ll

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt < %s -passes=instcombine -S | FileCheck %s
;
; Verify that memchr calls with a string consisting of all the same
; characters are folded and those with mixed strings are not.

declare i8* @memchr(i8*, i32, i64)

@a00000 = constant [5 x i8] zeroinitializer
@a11111 = constant [5 x i8] c"\01\01\01\01\01"
@a111122 = constant [6 x i8] c"\01\01\01\01\02\02"
@a1110111 = constant [7 x i8] c"\01\01\01\00\01\01\01"


; Fold memchr(a00000, C, 5) to *a00000 == C ? a00000 : null.
; TODO: This depends on getConstantStringInfo() being able to handle
; implicitly zeroed out constants.

define i8* @fold_memchr_a00000_c_5(i32 %C) {
; CHECK-LABEL: @fold_memchr_a00000_c_5(
; CHECK-NEXT:    [[RET:%.*]] = call i8* @memchr(i8* noundef nonnull dereferenceable(1) getelementptr inbounds ([5 x i8], [5 x i8]* @a00000, i64 0, i64 0), i32 [[C:%.*]], i64 5)
; CHECK-NEXT:    ret i8* [[RET]]
;

  %ptr = getelementptr [5 x i8], [5 x i8]* @a00000, i64 0, i64 0
  %ret = call i8* @memchr(i8* %ptr, i32 %C, i64 5)
  ret i8* %ret
}


; Fold memchr(a11111, C, 5) to *a11111 == C ? a11111 : null.

define i8* @fold_memchr_a11111_c_5(i32 %C) {
; CHECK-LABEL: @fold_memchr_a11111_c_5(
; CHECK-NEXT:    [[TMP1:%.*]] = trunc i32 [[C:%.*]] to i8
; CHECK-NEXT:    [[TMP2:%.*]] = icmp eq i8 [[TMP1]], 1
; CHECK-NEXT:    [[MEMCHR_SEL2:%.*]] = select i1 [[TMP2]], i8* getelementptr inbounds ([5 x i8], [5 x i8]* @a11111, i64 0, i64 0), i8* null
; CHECK-NEXT:    ret i8* [[MEMCHR_SEL2]]
;

  %ptr = getelementptr [5 x i8], [5 x i8]* @a11111, i64 0, i64 0
  %ret = call i8* @memchr(i8* %ptr, i32 %C, i64 5)
  ret i8* %ret
}


; Fold memchr(a11111, C, N) to N && *a11111 == C ? a11111 : null,
; on the assumption that N is in bounds.

define i8* @fold_memchr_a11111_c_n(i32 %C, i64 %N) {
; CHECK-LABEL: @fold_memchr_a11111_c_n(
; CHECK-NEXT:    [[TMP1:%.*]] = trunc i32 [[C:%.*]] to i8
; CHECK-NEXT:    [[TMP2:%.*]] = icmp eq i8 [[TMP1]], 1
; CHECK-NEXT:    [[TMP3:%.*]] = icmp ne i64 [[N:%.*]], 0
; CHECK-NEXT:    [[TMP4:%.*]] = and i1 [[TMP3]], [[TMP2]]
; CHECK-NEXT:    [[MEMCHR_SEL2:%.*]] = select i1 [[TMP4]], i8* getelementptr inbounds ([5 x i8], [5 x i8]* @a11111, i64 0, i64 0), i8* null
; CHECK-NEXT:    ret i8* [[MEMCHR_SEL2]]
;

  %ptr = getelementptr [5 x i8], [5 x i8]* @a11111, i64 0, i64 0
  %ret = call i8* @memchr(i8* %ptr, i32 %C, i64 %N)
  ret i8* %ret
}


; Fold memchr(a111122, C, N) to
;   N != 0 && C == 1 ? a111122 : N > 4 && C == 2 ? a111122 + 4 : null.

define i8* @fold_memchr_a111122_c_n(i32 %C, i64 %N) {
; CHECK-LABEL: @fold_memchr_a111122_c_n(
; CHECK-NEXT:    [[TMP1:%.*]] = trunc i32 [[C:%.*]] to i8
; CHECK-NEXT:    [[TMP2:%.*]] = icmp eq i8 [[TMP1]], 2
; CHECK-NEXT:    [[TMP3:%.*]] = icmp ugt i64 [[N:%.*]], 4
; CHECK-NEXT:    [[TMP4:%.*]] = and i1 [[TMP2]], [[TMP3]]
; CHECK-NEXT:    [[MEMCHR_SEL1:%.*]] = select i1 [[TMP4]], i8* getelementptr inbounds ([6 x i8], [6 x i8]* @a111122, i64 0, i64 4), i8* null
; CHECK-NEXT:    [[TMP5:%.*]] = icmp eq i8 [[TMP1]], 1
; CHECK-NEXT:    [[TMP6:%.*]] = icmp ne i64 [[N]], 0
; CHECK-NEXT:    [[TMP7:%.*]] = and i1 [[TMP6]], [[TMP5]]
; CHECK-NEXT:    [[MEMCHR_SEL2:%.*]] = select i1 [[TMP7]], i8* getelementptr inbounds ([6 x i8], [6 x i8]* @a111122, i64 0, i64 0), i8* [[MEMCHR_SEL1]]
; CHECK-NEXT:    ret i8* [[MEMCHR_SEL2]]
;

  %ptr = getelementptr [6 x i8], [6 x i8]* @a111122, i64 0, i64 0
  %ret = call i8* @memchr(i8* %ptr, i32 %C, i64 %N)
  ret i8* %ret
}


; Fold memchr(a1110111, C, 3) to a1110111[2] == C ? a1110111 : null.

define i8* @fold_memchr_a1110111_c_3(i32 %C) {
; CHECK-LABEL: @fold_memchr_a1110111_c_3(
; CHECK-NEXT:    [[TMP1:%.*]] = trunc i32 [[C:%.*]] to i8
; CHECK-NEXT:    [[TMP2:%.*]] = icmp eq i8 [[TMP1]], 1
; CHECK-NEXT:    [[MEMCHR_SEL2:%.*]] = select i1 [[TMP2]], i8* getelementptr inbounds ([7 x i8], [7 x i8]* @a1110111, i64 0, i64 0), i8* null
; CHECK-NEXT:    ret i8* [[MEMCHR_SEL2]]
;

  %ptr = getelementptr [7 x i8], [7 x i8]* @a1110111, i64 0, i64 0
  %ret = call i8* @memchr(i8* %ptr, i32 %C, i64 3)
  ret i8* %ret
}


; Don't fold memchr(a1110111, C, 4).

define i8* @call_memchr_a1110111_c_4(i32 %C) {
; CHECK-LABEL: @call_memchr_a1110111_c_4(
; CHECK-NEXT:    [[TMP1:%.*]] = trunc i32 [[C:%.*]] to i8
; CHECK-NEXT:    [[TMP2:%.*]] = icmp eq i8 [[TMP1]], 0
; CHECK-NEXT:    [[MEMCHR_SEL1:%.*]] = select i1 [[TMP2]], i8* getelementptr inbounds ([7 x i8], [7 x i8]* @a1110111, i64 0, i64 3), i8* null
; CHECK-NEXT:    [[TMP3:%.*]] = icmp eq i8 [[TMP1]], 1
; CHECK-NEXT:    [[MEMCHR_SEL2:%.*]] = select i1 [[TMP3]], i8* getelementptr inbounds ([7 x i8], [7 x i8]* @a1110111, i64 0, i64 0), i8* [[MEMCHR_SEL1]]
; CHECK-NEXT:    ret i8* [[MEMCHR_SEL2]]
;

  %ptr = getelementptr [7 x i8], [7 x i8]* @a1110111, i64 0, i64 0
  %ret = call i8* @memchr(i8* %ptr, i32 %C, i64 4)
  ret i8* %ret
}


; Don't fold memchr(a1110111, C, 7).

define i8* @call_memchr_a1110111_c_7(i32 %C) {
; CHECK-LABEL: @call_memchr_a1110111_c_7(
; CHECK-NEXT:    [[RET:%.*]] = call i8* @memchr(i8* noundef nonnull dereferenceable(1) getelementptr inbounds ([7 x i8], [7 x i8]* @a1110111, i64 0, i64 0), i32 [[C:%.*]], i64 7)
; CHECK-NEXT:    ret i8* [[RET]]
;

  %ptr = getelementptr [7 x i8], [7 x i8]* @a1110111, i64 0, i64 0
  %ret = call i8* @memchr(i8* %ptr, i32 %C, i64 7)
  ret i8* %ret
}


; Don't fold memchr(a1110111, C, N).

define i8* @call_memchr_a1110111_c_n(i32 %C, i64 %N) {
; CHECK-LABEL: @call_memchr_a1110111_c_n(
; CHECK-NEXT:    [[RET:%.*]] = call i8* @memchr(i8* getelementptr inbounds ([7 x i8], [7 x i8]* @a1110111, i64 0, i64 0), i32 [[C:%.*]], i64 [[N:%.*]])
; CHECK-NEXT:    ret i8* [[RET]]
;

  %ptr = getelementptr [7 x i8], [7 x i8]* @a1110111, i64 0, i64 0
  %ret = call i8* @memchr(i8* %ptr, i32 %C, i64 %N)
  ret i8* %ret
}