test/Transforms/InstCombine/strncmp-6.ll

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt < %s -passes=instcombine -S | FileCheck %s
;
; Exercise folding of strncmp calls with constant arrays including both
; negative and positive characters and both constant and nonconstant sizes.

declare i32 @strncmp(ptr, ptr, i64)

@a = constant [7 x i8] c"abcdef\7f"
@b = constant [7 x i8] c"abcdef\80"


; Exercise strncmp(A + C, B + C, 2) folding of small arrays that differ in
; a character with the opposite sign and a constant size.

define void @fold_strncmp_cst_cst(ptr %pcmp) {
; CHECK-LABEL: @fold_strncmp_cst_cst(
; CHECK-NEXT:    store i32 -1, ptr [[PCMP:%.*]], align 4
; CHECK-NEXT:    [[SB5_A5:%.*]] = getelementptr i32, ptr [[PCMP]], i64 1
; CHECK-NEXT:    store i32 1, ptr [[SB5_A5]], align 4
; CHECK-NEXT:    [[SA6_B6:%.*]] = getelementptr i32, ptr [[PCMP]], i64 2
; CHECK-NEXT:    store i32 -1, ptr [[SA6_B6]], align 4
; CHECK-NEXT:    [[SB6_A6:%.*]] = getelementptr i32, ptr [[PCMP]], i64 3
; CHECK-NEXT:    store i32 1, ptr [[SB6_A6]], align 4
; CHECK-NEXT:    ret void
;
  %p5 = getelementptr [7 x i8], ptr @a, i64 0, i64 5
  %p6 = getelementptr [7 x i8], ptr @a, i64 0, i64 6

  %q5 = getelementptr [7 x i8], ptr @b, i64 0, i64 5
  %q6 = getelementptr [7 x i8], ptr @b, i64 0, i64 6

  ; Fold strncmp(a + 5, b + 5, 2) to -1.
  %ca5_b5 = call i32 @strncmp(ptr %p5, ptr %q5, i64 2)
  store i32 %ca5_b5, ptr %pcmp

  ; Fold strncmp(b + 5, a + 5, 2) to +1.
  %cb5_a5 = call i32 @strncmp(ptr %q5, ptr %p5, i64 2)
  %sb5_a5 = getelementptr i32, ptr %pcmp, i64 1
  store i32 %cb5_a5, ptr %sb5_a5

  ; Fold strncmp(a + 6, b + 6, 1) to -1.
  %ca6_b6 = call i32 @strncmp(ptr %p6, ptr %q6, i64 1)
  %sa6_b6 = getelementptr i32, ptr %pcmp, i64 2
  store i32 %ca6_b6, ptr %sa6_b6

  ; Fold strncmp(b + 6, a + 6, 1) to  +1.
  %cb6_a6 = call i32 @strncmp(ptr %q6, ptr %p6, i64 1)
  %sb6_a6 = getelementptr i32, ptr %pcmp, i64 3
  store i32 %cb6_a6, ptr %sb6_a6

  ret void
}


; Exercise strncmp(A, B, N) folding of arrays that differ in a character
; with the opposite sign and a variable size

define void @fold_strncmp_cst_var(ptr %pcmp, i64 %n) {
; CHECK-LABEL: @fold_strncmp_cst_var(
; CHECK-NEXT:    [[TMP1:%.*]] = icmp ugt i64 [[N:%.*]], 6
; CHECK-NEXT:    [[CA0_B0:%.*]] = sext i1 [[TMP1]] to i32
; CHECK-NEXT:    store i32 [[CA0_B0]], ptr [[PCMP:%.*]], align 4
; CHECK-NEXT:    [[TMP2:%.*]] = icmp ugt i64 [[N]], 6
; CHECK-NEXT:    [[CB0_A0:%.*]] = zext i1 [[TMP2]] to i32
; CHECK-NEXT:    [[SB0_A0:%.*]] = getelementptr i32, ptr [[PCMP]], i64 1
; CHECK-NEXT:    store i32 [[CB0_A0]], ptr [[SB0_A0]], align 4
; CHECK-NEXT:    [[TMP3:%.*]] = icmp ne i64 [[N]], 0
; CHECK-NEXT:    [[CA6_B6:%.*]] = sext i1 [[TMP3]] to i32
; CHECK-NEXT:    [[SA6_B6:%.*]] = getelementptr i32, ptr [[PCMP]], i64 2
; CHECK-NEXT:    store i32 [[CA6_B6]], ptr [[SA6_B6]], align 4
; CHECK-NEXT:    [[TMP4:%.*]] = icmp ne i64 [[N]], 0
; CHECK-NEXT:    [[CB6_A6:%.*]] = zext i1 [[TMP4]] to i32
; CHECK-NEXT:    [[SB6_A6:%.*]] = getelementptr i32, ptr [[PCMP]], i64 3
; CHECK-NEXT:    store i32 [[CB6_A6]], ptr [[SB6_A6]], align 4
; CHECK-NEXT:    ret void
;
  %p6 = getelementptr [7 x i8], ptr @a, i64 0, i64 6

  %q6 = getelementptr [7 x i8], ptr @b, i64 0, i64 6

  ; Fold strncmp(a, b, n) to -1.
  %ca0_b0 = call i32 @strncmp(ptr @a, ptr @b, i64 %n)
  store i32 %ca0_b0, ptr %pcmp

  ; Fold strncmp(b, a, n) to +1.
  %cb0_a0 = call i32 @strncmp(ptr @b, ptr @a, i64 %n)
  %sb0_a0 = getelementptr i32, ptr %pcmp, i64 1
  store i32 %cb0_a0, ptr %sb0_a0

  ; Fold strncmp(a + 6, b + 6, n) to -1.
  %ca6_b6 = call i32 @strncmp(ptr %p6, ptr %q6, i64 %n)
  %sa6_b6 = getelementptr i32, ptr %pcmp, i64 2
  store i32 %ca6_b6, ptr %sa6_b6

  ; Fold strncmp(b + 6, a + 6, n) to +1.
  %cb6_a6 = call i32 @strncmp(ptr %q6, ptr %p6, i64 %n)
  %sb6_a6 = getelementptr i32, ptr %pcmp, i64 3
  store i32 %cb6_a6, ptr %sb6_a6

  ret void
}