llvm/test/Transforms/InstCombine/strcmp-1.ll

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; Test that the strcmp library call simplifier works correctly.
; RUN: opt < %s -passes=instcombine -S | FileCheck %s --check-prefix=NOBCMP
; RUN: opt < %s -passes=instcombine -mtriple=unknown-unknown-linux-gnu -S | FileCheck %s --check-prefix=BCMP

target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"

@hello = constant [6 x i8] c"hello\00"
@hell = constant [5 x i8] c"hell\00"
@bell = constant [5 x i8] c"bell\00"
@null = constant [1 x i8] zeroinitializer

declare i32 @strcmp(ptr, ptr)

; strcmp("", x) -> -*x
define i32 @test1(ptr %str2) {
; CHECK-LABEL: @test1(
; CHECK: %strcmpload = load i8, ptr %str
; CHECK: %1 = zext i8 %strcmpload to i32
; CHECK: %2 = sub nsw i32 0, %1
; CHECK: ret i32 %2
; NOBCMP-LABEL: @test1(
; NOBCMP-NEXT:    [[STRCMPLOAD:%.*]] = load i8, ptr [[STR2:%.*]], align 1
; NOBCMP-NEXT:    [[TMP1:%.*]] = zext i8 [[STRCMPLOAD]] to i32
; NOBCMP-NEXT:    [[TEMP1:%.*]] = sub nsw i32 0, [[TMP1]]
; NOBCMP-NEXT:    ret i32 [[TEMP1]]
;
; BCMP-LABEL: @test1(
; BCMP-NEXT:    [[STRCMPLOAD:%.*]] = load i8, ptr [[STR2:%.*]], align 1
; BCMP-NEXT:    [[TMP1:%.*]] = zext i8 [[STRCMPLOAD]] to i32
; BCMP-NEXT:    [[TEMP1:%.*]] = sub nsw i32 0, [[TMP1]]
; BCMP-NEXT:    ret i32 [[TEMP1]]
;
  %temp1 = call i32 @strcmp(ptr @null, ptr %str2)
  ret i32 %temp1

}

; strcmp(x, "") -> *x
define i32 @test2(ptr %str1) {
; CHECK-LABEL: @test2(
; CHECK: %strcmpload = load i8, ptr %str
; CHECK: %1 = zext i8 %strcmpload to i32
; CHECK: ret i32 %1
; NOBCMP-LABEL: @test2(
; NOBCMP-NEXT:    [[STRCMPLOAD:%.*]] = load i8, ptr [[STR1:%.*]], align 1
; NOBCMP-NEXT:    [[TEMP1:%.*]] = zext i8 [[STRCMPLOAD]] to i32
; NOBCMP-NEXT:    ret i32 [[TEMP1]]
;
; BCMP-LABEL: @test2(
; BCMP-NEXT:    [[STRCMPLOAD:%.*]] = load i8, ptr [[STR1:%.*]], align 1
; BCMP-NEXT:    [[TEMP1:%.*]] = zext i8 [[STRCMPLOAD]] to i32
; BCMP-NEXT:    ret i32 [[TEMP1]]
;
  %temp1 = call i32 @strcmp(ptr %str1, ptr @null)
  ret i32 %temp1
}

; strcmp(x, y)  -> cnst
define i32 @test3() {
; CHECK-LABEL: @test3(
; CHECK: ret i32 -1
; NOBCMP-LABEL: @test3(
; NOBCMP-NEXT:    ret i32 -1
;
; BCMP-LABEL: @test3(
; BCMP-NEXT:    ret i32 -1
;
  %temp1 = call i32 @strcmp(ptr @hell, ptr @hello)
  ret i32 %temp1
}

define i32 @test4() {
; CHECK-LABEL: @test4(
; CHECK: ret i32 1
; NOBCMP-LABEL: @test4(
; NOBCMP-NEXT:    ret i32 1
;
; BCMP-LABEL: @test4(
; BCMP-NEXT:    ret i32 1
;
  %temp1 = call i32 @strcmp(ptr @hell, ptr @null)
  ret i32 %temp1
}

; strcmp(x, y)   -> memcmp(x, y, <known length>)
; (This transform is rather difficult to trigger in a useful manner)
define i32 @test5(i1 %b) {
; CHECK-LABEL: @test5(
; CHECK: %memcmp = call i32 @memcmp(ptr @hello, ptr %str2, i32 5)
; CHECK: ret i32 %memcmp
; NOBCMP-LABEL: @test5(
; NOBCMP-NEXT:    [[STR2:%.*]] = select i1 [[B:%.*]], ptr @hell, ptr @bell
; NOBCMP-NEXT:    [[MEMCMP:%.*]] = call i32 @memcmp(ptr noundef nonnull dereferenceable(5) @hello, ptr noundef nonnull dereferenceable(5) [[STR2]], i32 5)
; NOBCMP-NEXT:    ret i32 [[MEMCMP]]
;
; BCMP-LABEL: @test5(
; BCMP-NEXT:    [[STR2:%.*]] = select i1 [[B:%.*]], ptr @hell, ptr @bell
; BCMP-NEXT:    [[MEMCMP:%.*]] = call i32 @memcmp(ptr noundef nonnull dereferenceable(5) @hello, ptr noundef nonnull dereferenceable(5) [[STR2]], i32 5)
; BCMP-NEXT:    ret i32 [[MEMCMP]]
;
  %str2 = select i1 %b, ptr @hell, ptr @bell
  %temp3 = call i32 @strcmp(ptr @hello, ptr %str2)
  ret i32 %temp3
}

; strcmp(x,x)  -> 0
define i32 @test6(ptr %str) {
; CHECK-LABEL: @test6(
; CHECK: ret i32 0
; NOBCMP-LABEL: @test6(
; NOBCMP-NEXT:    ret i32 0
;
; BCMP-LABEL: @test6(
; BCMP-NEXT:    ret i32 0
;
  %temp1 = call i32 @strcmp(ptr %str, ptr %str)
  ret i32 %temp1
}

; strcmp(x, y) == 0  -> bcmp(x, y, <known length>)
define i1 @test7(i1 %b) {
; NOBCMP-LABEL: @test7(
; NOBCMP-NEXT:    [[STR2:%.*]] = select i1 [[B:%.*]], ptr @hell, ptr @bell
; NOBCMP-NEXT:    [[MEMCMP:%.*]] = call i32 @memcmp(ptr noundef nonnull dereferenceable(5) @hello, ptr noundef nonnull dereferenceable(5) [[STR2]], i32 5)
; NOBCMP-NEXT:    [[RES:%.*]] = icmp eq i32 [[MEMCMP]], 0
; NOBCMP-NEXT:    ret i1 [[RES]]
;
; BCMP-LABEL: @test7(
; BCMP-NEXT:    [[STR2:%.*]] = select i1 [[B:%.*]], ptr @hell, ptr @bell
; BCMP-NEXT:    [[BCMP:%.*]] = call i32 @bcmp(ptr noundef nonnull dereferenceable(5) @hello, ptr noundef nonnull dereferenceable(5) [[STR2]], i32 5)
; BCMP-NEXT:    [[RES:%.*]] = icmp eq i32 [[BCMP]], 0
; BCMP-NEXT:    ret i1 [[RES]]
;


  %str2 = select i1 %b, ptr @hell, ptr @bell
  %temp3 = call i32 @strcmp(ptr @hello, ptr %str2)
  %res = icmp eq i32 %temp3, 0
  ret i1 %res
}