test/Transforms/InstCombine/strcall-no-nul.ll - llvm-project/llvm - Git at Google

 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
 ; RUN: opt < %s -passes=instcombine -S | FileCheck %s
 ;
 ; Verify that calls with arguments with pointers just past the end of
 ; a string to [a subset of] library functions that expect nul-terminated
 ; strings as arguments are folded to safe values.  The rationale is that
 ; since they are undefined and even though folding them isn't important
 ; for efficiency and prevents sanitizers from detecting and reporting
 ; them, sanitizers usually don't run, and transforming such invalid
 ; calls to something valid is safer than letting the program run off
 ; the rails.  See the Safe Optimizations for Sanitizers RFC for
 ; an in-depth discussion of the trade-offs:
 ; https://discourse.llvm.org/t/rfc-safe-optimizations-for-sanitizers

 declare ptr @strchr(ptr, i32)
 declare ptr @strrchr(ptr, i32)
 declare i32 @strcmp(ptr, ptr)
 declare i32 @strncmp(ptr, ptr, i64)
 declare ptr @strstr(ptr, ptr)

 declare ptr @stpcpy(ptr, ptr)
 declare ptr @strcpy(ptr, ptr)
 declare ptr @stpncpy(ptr, ptr, i64)
 declare ptr @strncpy(ptr, ptr, i64)

 declare i64 @strlen(ptr)
 declare i64 @strnlen(ptr, i64)

 declare ptr @strpbrk(ptr, ptr)

 declare i64 @strspn(ptr, ptr)
 declare i64 @strcspn(ptr, ptr)

 declare i32 @atoi(ptr)
 declare i64 @atol(ptr)
 declare i64 @atoll(ptr)
 declare i64 @strtol(ptr, ptr, i32)
 declare i64 @strtoll(ptr, ptr, i32)
 declare i64 @strtoul(ptr, ptr, i32)
 declare i64 @strtoull(ptr, ptr, i32)

 declare i32 @sprintf(ptr, ptr, ...)
 declare i32 @snprintf(ptr, i64, ptr, ...)


 @a5 = constant [5 x i8] c"%s\0045";


 ; Fold strchr(a5 + 5, '\0') to null.

 define ptr @fold_strchr_past_end() {
 ; CHECK-LABEL: @fold_strchr_past_end(
 ; CHECK-NEXT:    ret ptr getelementptr inbounds ([5 x i8], ptr @a5, i64 1, i64 0)
 ;
   %p = getelementptr [5 x i8], ptr @a5, i32 0, i32 5
   %q = call ptr @strchr(ptr %p, i32 0)
   ret ptr %q
 }

 ; Fold strcmp(a5, a5 + 5) (and vice versa) to null.

 define void @fold_strcmp_past_end(ptr %pcmp) {
 ; CHECK-LABEL: @fold_strcmp_past_end(
 ; CHECK-NEXT:    store i32 1, ptr [[PCMP:%.*]], align 4
 ; CHECK-NEXT:    [[PC50:%.*]] = getelementptr i8, ptr [[PCMP]], i64 4
 ; CHECK-NEXT:    store i32 -1, ptr [[PC50]], align 4
 ; CHECK-NEXT:    ret void
 ;
   %p5 = getelementptr [5 x i8], ptr @a5, i32 0, i32 5

   %c05 = call i32 @strcmp(ptr @a5, ptr %p5)
   store i32 %c05, ptr %pcmp

   %c50 = call i32 @strcmp(ptr %p5, ptr @a5)
   %pc50 = getelementptr i32, ptr %pcmp, i32 1
   store i32 %c50, ptr %pc50

   ret void
 }


 ; Likewise, fold strncmp(a5, a5 + 5, 5) (and vice versa) to null.

 define void @fold_strncmp_past_end(ptr %pcmp) {
 ; CHECK-LABEL: @fold_strncmp_past_end(
 ; CHECK-NEXT:    store i32 1, ptr [[PCMP:%.*]], align 4
 ; CHECK-NEXT:    [[PC50:%.*]] = getelementptr i8, ptr [[PCMP]], i64 4
 ; CHECK-NEXT:    store i32 -1, ptr [[PC50]], align 4
 ; CHECK-NEXT:    ret void
 ;
   %p5 = getelementptr [5 x i8], ptr @a5, i32 0, i32 5

   %c05 = call i32 @strncmp(ptr @a5, ptr %p5, i64 5)
   store i32 %c05, ptr %pcmp

   %c50 = call i32 @strncmp(ptr %p5, ptr @a5, i64 5)
   %pc50 = getelementptr i32, ptr %pcmp, i32 1
   store i32 %c50, ptr %pc50

   ret void
 }


 ; Fold strrchr(a5 + 5, '\0') to poison (it's UB).

 define ptr @fold_strrchr_past_end(i32 %c) {
 ; CHECK-LABEL: @fold_strrchr_past_end(
 ; CHECK-NEXT:    ret ptr poison
 ;
   %p5 = getelementptr [5 x i8], ptr @a5, i32 0, i32 5
   %r = call ptr @strrchr(ptr %p5, i32 0)
   ret ptr %r
 }


 ; Fold strstr(a5 + 5, a5) (and vice versa) to null.

 define void @fold_strstr_past_end(ptr %psub) {
 ; CHECK-LABEL: @fold_strstr_past_end(
 ; CHECK-NEXT:    store ptr @a5, ptr [[PSUB:%.*]], align 8
 ; CHECK-NEXT:    [[PS50:%.*]] = getelementptr i8, ptr [[PSUB]], i64 8
 ; CHECK-NEXT:    store ptr null, ptr [[PS50]], align 8
 ; CHECK-NEXT:    ret void
 ;
   %p5 = getelementptr [5 x i8], ptr @a5, i32 0, i32 5

   %s05 = call ptr @strstr(ptr @a5, ptr %p5)
   store ptr %s05, ptr %psub

   %s50 = call ptr @strstr(ptr %p5, ptr @a5)
   %ps50 = getelementptr ptr, ptr %psub, i32 1
   store ptr %s50, ptr %ps50

   ret void
 }


 ; Fold strlen(a5 + 5) to 0.

 define i64 @fold_strlen_past_end() {
 ; CHECK-LABEL: @fold_strlen_past_end(
 ; CHECK-NEXT:    ret i64 0
 ;
   %p5 = getelementptr [5 x i8], ptr @a5, i32 0, i32 5
   %r = call i64 @strlen(ptr %p5)
   ret i64 %r
 }


 ; TODO: Fold stpcpy(dst, a5 + 5) to (*dst = '\0', dst).

 define ptr @fold_stpcpy_past_end(ptr %dst) {
 ; CHECK-LABEL: @fold_stpcpy_past_end(
 ; CHECK-NEXT:    ret ptr [[DST:%.*]]
 ;
   %p5 = getelementptr [5 x i8], ptr @a5, i32 0, i32 5
   %r = call ptr @strcpy(ptr %dst, ptr %p5)
   ret ptr %r
 }


 ; TODO: Fold strcpy(dst, a5 + 5) to (*dst = '\0', dst).

 define ptr @fold_strcpy_past_end(ptr %dst) {
 ; CHECK-LABEL: @fold_strcpy_past_end(
 ; CHECK-NEXT:    ret ptr [[DST:%.*]]
 ;
   %p5 = getelementptr [5 x i8], ptr @a5, i32 0, i32 5
   %r = call ptr @strcpy(ptr %dst, ptr %p5)
   ret ptr %r
 }


 ; TODO: Fold stpncpy(dst, a5 + 5, 5) to (memset(dst, 0, 5), dst + 5).

 define ptr @fold_stpncpy_past_end(ptr %dst) {
 ; CHECK-LABEL: @fold_stpncpy_past_end(
 ; CHECK-NEXT:    call void @llvm.memset.p0.i64(ptr noundef nonnull align 1 dereferenceable(5) [[DST:%.*]], i8 0, i64 5, i1 false)
 ; CHECK-NEXT:    ret ptr [[DST]]
 ;
   %p5 = getelementptr [5 x i8], ptr @a5, i32 0, i32 5
   %r = call ptr @strncpy(ptr %dst, ptr %p5, i64 5)
   ret ptr %r
 }


 ; TODO: Fold strncpy(dst, a5 + 5, 5) to memset(dst, 0, 5).

 define ptr @fold_strncpy_past_end(ptr %dst) {
 ; CHECK-LABEL: @fold_strncpy_past_end(
 ; CHECK-NEXT:    call void @llvm.memset.p0.i64(ptr noundef nonnull align 1 dereferenceable(5) [[DST:%.*]], i8 0, i64 5, i1 false)
 ; CHECK-NEXT:    ret ptr [[DST]]
 ;
   %p5 = getelementptr [5 x i8], ptr @a5, i32 0, i32 5
   %r = call ptr @strncpy(ptr %dst, ptr %p5, i64 5)
   ret ptr %r
 }


 ; Fold strpbrk(a5, a5 + 5) (and vice versa) to null.

 define void @fold_strpbrk_past_end(ptr %psub) {
 ; CHECK-LABEL: @fold_strpbrk_past_end(
 ; CHECK-NEXT:    store ptr null, ptr [[PSUB:%.*]], align 8
 ; CHECK-NEXT:    [[PS50:%.*]] = getelementptr i8, ptr [[PSUB]], i64 8
 ; CHECK-NEXT:    store ptr null, ptr [[PS50]], align 8
 ; CHECK-NEXT:    ret void
 ;
   %p5 = getelementptr [5 x i8], ptr @a5, i32 0, i32 5

   %s05 = call ptr @strpbrk(ptr @a5, ptr %p5)
   store ptr %s05, ptr %psub

   %s50 = call ptr @strpbrk(ptr %p5, ptr @a5)
   %ps50 = getelementptr ptr, ptr %psub, i32 1
   store ptr %s50, ptr %ps50

   ret void
 }


 ; Fold strspn(a5, a5 + 5) (and vice versa) to null.

 define void @fold_strspn_past_end(ptr %poff) {
 ; CHECK-LABEL: @fold_strspn_past_end(
 ; CHECK-NEXT:    store i64 0, ptr [[POFF:%.*]], align 4
 ; CHECK-NEXT:    [[PO50:%.*]] = getelementptr i8, ptr [[POFF]], i64 8
 ; CHECK-NEXT:    store i64 0, ptr [[PO50]], align 4
 ; CHECK-NEXT:    ret void
 ;
   %p5 = getelementptr [5 x i8], ptr @a5, i32 0, i32 5

   %o05 = call i64 @strspn(ptr @a5, ptr %p5)
   store i64 %o05, ptr %poff

   %o50 = call i64 @strspn(ptr %p5, ptr @a5)
   %po50 = getelementptr i64, ptr %poff, i32 1
   store i64 %o50, ptr %po50

   ret void
 }


 ; Fold strcspn(a5, a5 + 5) (and vice versa) to null.

 define void @fold_strcspn_past_end(ptr %poff) {
 ; CHECK-LABEL: @fold_strcspn_past_end(
 ; CHECK-NEXT:    store i64 2, ptr [[POFF:%.*]], align 4
 ; CHECK-NEXT:    [[PO50:%.*]] = getelementptr i8, ptr [[POFF]], i64 8
 ; CHECK-NEXT:    store i64 0, ptr [[PO50]], align 4
 ; CHECK-NEXT:    ret void
 ;
   %p5 = getelementptr [5 x i8], ptr @a5, i32 0, i32 5

   %o05 = call i64 @strcspn(ptr @a5, ptr %p5)
   store i64 %o05, ptr %poff

   %o50 = call i64 @strcspn(ptr %p5, ptr @a5)
   %po50 = getelementptr i64, ptr %poff, i32 1
   store i64 %o50, ptr %po50

   ret void
 }


 ; TODO: Fold the 32-bit atoi(a5 + 5) to zero.
 ; Verify that processing the invalid call doesn't run into trouble.

 define i32 @fold_atoi_past_end() {
 ; CHECK-LABEL: @fold_atoi_past_end(
 ; CHECK-NEXT:    [[I:%.*]] = call i32 @atoi(ptr nocapture nonnull getelementptr inbounds ([5 x i8], ptr @a5, i64 1, i64 0))
 ; CHECK-NEXT:    ret i32 [[I]]
 ;
   %p5 = getelementptr [5 x i8], ptr @a5, i32 0, i32 5
   %i = call i32 @atoi(ptr %p5)
   ret i32 %i
 }

 ; TODO: Likewise, fold the 64-bit atol(a5 + 5) to zero, and similarly
 ; for atoll and strtrol and similar.
 ; Verify that processing the invalid call doesn't run into trouble.

 define void @fold_atol_strtol_past_end(ptr %ps) {
 ; CHECK-LABEL: @fold_atol_strtol_past_end(
 ; CHECK-NEXT:    [[I0:%.*]] = call i64 @atol(ptr nocapture nonnull getelementptr inbounds ([5 x i8], ptr @a5, i64 1, i64 0))
 ; CHECK-NEXT:    store i64 [[I0]], ptr [[PS:%.*]], align 4
 ; CHECK-NEXT:    [[I1:%.*]] = call i64 @atoll(ptr nocapture nonnull getelementptr inbounds ([5 x i8], ptr @a5, i64 1, i64 0))
 ; CHECK-NEXT:    [[P1:%.*]] = getelementptr i8, ptr [[PS]], i64 8
 ; CHECK-NEXT:    store i64 [[I1]], ptr [[P1]], align 4
 ; CHECK-NEXT:    [[I2:%.*]] = call i64 @strtol(ptr nocapture nonnull getelementptr inbounds ([5 x i8], ptr @a5, i64 1, i64 0), ptr null, i32 0)
 ; CHECK-NEXT:    [[P2:%.*]] = getelementptr i8, ptr [[PS]], i64 16
 ; CHECK-NEXT:    store i64 [[I2]], ptr [[P2]], align 4
 ; CHECK-NEXT:    [[I3:%.*]] = call i64 @strtoul(ptr nocapture nonnull getelementptr inbounds ([5 x i8], ptr @a5, i64 1, i64 0), ptr null, i32 8)
 ; CHECK-NEXT:    [[P3:%.*]] = getelementptr i8, ptr [[PS]], i64 24
 ; CHECK-NEXT:    store i64 [[I3]], ptr [[P3]], align 4
 ; CHECK-NEXT:    [[I4:%.*]] = call i64 @strtoll(ptr nocapture nonnull getelementptr inbounds ([5 x i8], ptr @a5, i64 1, i64 0), ptr null, i32 10)
 ; CHECK-NEXT:    [[P4:%.*]] = getelementptr i8, ptr [[PS]], i64 32
 ; CHECK-NEXT:    store i64 [[I4]], ptr [[P4]], align 4
 ; CHECK-NEXT:    [[I5:%.*]] = call i64 @strtoul(ptr nocapture nonnull getelementptr inbounds ([5 x i8], ptr @a5, i64 1, i64 0), ptr null, i32 16)
 ; CHECK-NEXT:    [[P5:%.*]] = getelementptr i8, ptr [[PS]], i64 40
 ; CHECK-NEXT:    store i64 [[I5]], ptr [[P5]], align 4
 ; CHECK-NEXT:    ret void
 ;
   %pa5 = getelementptr [5 x i8], ptr @a5, i32 0, i32 5

   %i0 = call i64 @atol(ptr %pa5)
   store i64 %i0, ptr %ps

   %i1 = call i64 @atoll(ptr %pa5)
   %p1 = getelementptr i64, ptr %ps, i32 1
   store i64 %i1, ptr %p1

   %i2 = call i64 @strtol(ptr %pa5, ptr null, i32 0)
   %p2 = getelementptr i64, ptr %ps, i32 2
   store i64 %i2, ptr %p2

   %i3 = call i64 @strtoul(ptr %pa5, ptr null, i32 8)
   %p3 = getelementptr i64, ptr %ps, i32 3
   store i64 %i3, ptr %p3

   %i4 = call i64 @strtoll(ptr %pa5, ptr null, i32 10)
   %p4 = getelementptr i64, ptr %ps, i32 4
   store i64 %i4, ptr %p4

   %i5 = call i64 @strtoul(ptr %pa5, ptr null, i32 16)
   %p5 = getelementptr i64, ptr %ps, i32 5
   store i64 %i5, ptr %p5

   ret void
 }


 ; Fold sprintf(dst, a5 + 5) to zero, and also
 ; TODO: fold sprintf(dst, "%s", a5 + 5) to zero.

 define void @fold_sprintf_past_end(ptr %pcnt, ptr %dst) {
 ; CHECK-LABEL: @fold_sprintf_past_end(
 ; CHECK-NEXT:    store i32 0, ptr [[PCNT:%.*]], align 4
 ; CHECK-NEXT:    [[PN05:%.*]] = getelementptr i8, ptr [[PCNT]], i64 4
 ; CHECK-NEXT:    store i32 0, ptr [[PN05]], align 4
 ; CHECK-NEXT:    ret void
 ;
   %p5 = getelementptr [5 x i8], ptr @a5, i32 0, i32 5

   %n5_ = call i32 (ptr, ptr, ...) @sprintf(ptr %dst, ptr %p5)
   store i32 %n5_, ptr %pcnt

   %n05 = call i32 (ptr, ptr, ...) @sprintf(ptr %dst, ptr @a5, ptr %p5)
   %pn05 = getelementptr i32, ptr %pcnt, i32 1
   store i32 %n05, ptr %pn05

   ret void
 }


 ; Fold snprintf(dst, n, a5 + 5) to zero, and also
 ; TODO: fold snprintf(dst, n, "%s", a5 + 5) to zero.

 define void @fold_snprintf_past_end(ptr %pcnt, ptr %dst, i64 %n) {
 ; CHECK-LABEL: @fold_snprintf_past_end(
 ; CHECK-NEXT:    [[N5_:%.*]] = call i32 (ptr, i64, ptr, ...) @snprintf(ptr [[DST:%.*]], i64 [[N:%.*]], ptr nonnull getelementptr inbounds ([5 x i8], ptr @a5, i64 1, i64 0))
 ; CHECK-NEXT:    store i32 [[N5_]], ptr [[PCNT:%.*]], align 4
 ; CHECK-NEXT:    [[N05:%.*]] = call i32 (ptr, i64, ptr, ...) @snprintf(ptr [[DST]], i64 [[N]], ptr nonnull @a5, ptr nonnull getelementptr inbounds ([5 x i8], ptr @a5, i64 1, i64 0))
 ; CHECK-NEXT:    [[PN05:%.*]] = getelementptr i8, ptr [[PCNT]], i64 4
 ; CHECK-NEXT:    store i32 [[N05]], ptr [[PN05]], align 4
 ; CHECK-NEXT:    ret void
 ;
   %p5 = getelementptr [5 x i8], ptr @a5, i32 0, i32 5

   %n5_ = call i32 (ptr, i64, ptr, ...) @snprintf(ptr %dst, i64 %n, ptr %p5)
   store i32 %n5_, ptr %pcnt

   %n05 = call i32 (ptr, i64, ptr, ...) @snprintf(ptr %dst, i64 %n, ptr @a5, ptr %p5)
   %pn05 = getelementptr i32, ptr %pcnt, i32 1
   store i32 %n05, ptr %pn05

   ret void
 }
	; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
	; RUN: opt < %s -passes=instcombine -S \| FileCheck %s
	;
	; Verify that calls with arguments with pointers just past the end of
	; a string to [a subset of] library functions that expect nul-terminated
	; strings as arguments are folded to safe values. The rationale is that
	; since they are undefined and even though folding them isn't important
	; for efficiency and prevents sanitizers from detecting and reporting
	; them, sanitizers usually don't run, and transforming such invalid
	; calls to something valid is safer than letting the program run off
	; the rails. See the Safe Optimizations for Sanitizers RFC for
	; an in-depth discussion of the trade-offs:
	; https://discourse.llvm.org/t/rfc-safe-optimizations-for-sanitizers

	declare ptr @strchr(ptr, i32)
	declare ptr @strrchr(ptr, i32)
	declare i32 @strcmp(ptr, ptr)
	declare i32 @strncmp(ptr, ptr, i64)
	declare ptr @strstr(ptr, ptr)

	declare ptr @stpcpy(ptr, ptr)
	declare ptr @strcpy(ptr, ptr)
	declare ptr @stpncpy(ptr, ptr, i64)
	declare ptr @strncpy(ptr, ptr, i64)

	declare i64 @strlen(ptr)
	declare i64 @strnlen(ptr, i64)

	declare ptr @strpbrk(ptr, ptr)

	declare i64 @strspn(ptr, ptr)
	declare i64 @strcspn(ptr, ptr)

	declare i32 @atoi(ptr)
	declare i64 @atol(ptr)
	declare i64 @atoll(ptr)
	declare i64 @strtol(ptr, ptr, i32)
	declare i64 @strtoll(ptr, ptr, i32)
	declare i64 @strtoul(ptr, ptr, i32)
	declare i64 @strtoull(ptr, ptr, i32)

	declare i32 @sprintf(ptr, ptr, ...)
	declare i32 @snprintf(ptr, i64, ptr, ...)


	@a5 = constant [5 x i8] c"%s\0045";


	; Fold strchr(a5 + 5, '\0') to null.

	define ptr @fold_strchr_past_end() {
	; CHECK-LABEL: @fold_strchr_past_end(
	; CHECK-NEXT: ret ptr getelementptr inbounds ([5 x i8], ptr @a5, i64 1, i64 0)
	;
	%p = getelementptr [5 x i8], ptr @a5, i32 0, i32 5
	%q = call ptr @strchr(ptr %p, i32 0)
	ret ptr %q
	}

	; Fold strcmp(a5, a5 + 5) (and vice versa) to null.

	define void @fold_strcmp_past_end(ptr %pcmp) {
	; CHECK-LABEL: @fold_strcmp_past_end(
	; CHECK-NEXT: store i32 1, ptr [[PCMP:%.*]], align 4
	; CHECK-NEXT: [[PC50:%.*]] = getelementptr i8, ptr [[PCMP]], i64 4
	; CHECK-NEXT: store i32 -1, ptr [[PC50]], align 4
	; CHECK-NEXT: ret void
	;
	%p5 = getelementptr [5 x i8], ptr @a5, i32 0, i32 5

	%c05 = call i32 @strcmp(ptr @a5, ptr %p5)
	store i32 %c05, ptr %pcmp

	%c50 = call i32 @strcmp(ptr %p5, ptr @a5)
	%pc50 = getelementptr i32, ptr %pcmp, i32 1
	store i32 %c50, ptr %pc50

	ret void
	}


	; Likewise, fold strncmp(a5, a5 + 5, 5) (and vice versa) to null.

	define void @fold_strncmp_past_end(ptr %pcmp) {
	; CHECK-LABEL: @fold_strncmp_past_end(
	; CHECK-NEXT: store i32 1, ptr [[PCMP:%.*]], align 4
	; CHECK-NEXT: [[PC50:%.*]] = getelementptr i8, ptr [[PCMP]], i64 4
	; CHECK-NEXT: store i32 -1, ptr [[PC50]], align 4
	; CHECK-NEXT: ret void
	;
	%p5 = getelementptr [5 x i8], ptr @a5, i32 0, i32 5

	%c05 = call i32 @strncmp(ptr @a5, ptr %p5, i64 5)
	store i32 %c05, ptr %pcmp

	%c50 = call i32 @strncmp(ptr %p5, ptr @a5, i64 5)
	%pc50 = getelementptr i32, ptr %pcmp, i32 1
	store i32 %c50, ptr %pc50

	ret void
	}


	; Fold strrchr(a5 + 5, '\0') to poison (it's UB).

	define ptr @fold_strrchr_past_end(i32 %c) {
	; CHECK-LABEL: @fold_strrchr_past_end(
	; CHECK-NEXT: ret ptr poison
	;
	%p5 = getelementptr [5 x i8], ptr @a5, i32 0, i32 5
	%r = call ptr @strrchr(ptr %p5, i32 0)
	ret ptr %r
	}


	; Fold strstr(a5 + 5, a5) (and vice versa) to null.

	define void @fold_strstr_past_end(ptr %psub) {
	; CHECK-LABEL: @fold_strstr_past_end(
	; CHECK-NEXT: store ptr @a5, ptr [[PSUB:%.*]], align 8
	; CHECK-NEXT: [[PS50:%.*]] = getelementptr i8, ptr [[PSUB]], i64 8
	; CHECK-NEXT: store ptr null, ptr [[PS50]], align 8
	; CHECK-NEXT: ret void
	;
	%p5 = getelementptr [5 x i8], ptr @a5, i32 0, i32 5

	%s05 = call ptr @strstr(ptr @a5, ptr %p5)
	store ptr %s05, ptr %psub

	%s50 = call ptr @strstr(ptr %p5, ptr @a5)
	%ps50 = getelementptr ptr, ptr %psub, i32 1
	store ptr %s50, ptr %ps50

	ret void
	}


	; Fold strlen(a5 + 5) to 0.

	define i64 @fold_strlen_past_end() {
	; CHECK-LABEL: @fold_strlen_past_end(
	; CHECK-NEXT: ret i64 0
	;
	%p5 = getelementptr [5 x i8], ptr @a5, i32 0, i32 5
	%r = call i64 @strlen(ptr %p5)
	ret i64 %r
	}


	; TODO: Fold stpcpy(dst, a5 + 5) to (*dst = '\0', dst).

	define ptr @fold_stpcpy_past_end(ptr %dst) {
	; CHECK-LABEL: @fold_stpcpy_past_end(
	; CHECK-NEXT: ret ptr [[DST:%.*]]
	;
	%p5 = getelementptr [5 x i8], ptr @a5, i32 0, i32 5
	%r = call ptr @strcpy(ptr %dst, ptr %p5)
	ret ptr %r
	}


	; TODO: Fold strcpy(dst, a5 + 5) to (*dst = '\0', dst).

	define ptr @fold_strcpy_past_end(ptr %dst) {
	; CHECK-LABEL: @fold_strcpy_past_end(
	; CHECK-NEXT: ret ptr [[DST:%.*]]
	;
	%p5 = getelementptr [5 x i8], ptr @a5, i32 0, i32 5
	%r = call ptr @strcpy(ptr %dst, ptr %p5)
	ret ptr %r
	}


	; TODO: Fold stpncpy(dst, a5 + 5, 5) to (memset(dst, 0, 5), dst + 5).

	define ptr @fold_stpncpy_past_end(ptr %dst) {
	; CHECK-LABEL: @fold_stpncpy_past_end(
	; CHECK-NEXT: call void @llvm.memset.p0.i64(ptr noundef nonnull align 1 dereferenceable(5) [[DST:%.*]], i8 0, i64 5, i1 false)
	; CHECK-NEXT: ret ptr [[DST]]
	;
	%p5 = getelementptr [5 x i8], ptr @a5, i32 0, i32 5
	%r = call ptr @strncpy(ptr %dst, ptr %p5, i64 5)
	ret ptr %r
	}


	; TODO: Fold strncpy(dst, a5 + 5, 5) to memset(dst, 0, 5).

	define ptr @fold_strncpy_past_end(ptr %dst) {
	; CHECK-LABEL: @fold_strncpy_past_end(
	; CHECK-NEXT: call void @llvm.memset.p0.i64(ptr noundef nonnull align 1 dereferenceable(5) [[DST:%.*]], i8 0, i64 5, i1 false)
	; CHECK-NEXT: ret ptr [[DST]]
	;
	%p5 = getelementptr [5 x i8], ptr @a5, i32 0, i32 5
	%r = call ptr @strncpy(ptr %dst, ptr %p5, i64 5)
	ret ptr %r
	}


	; Fold strpbrk(a5, a5 + 5) (and vice versa) to null.

	define void @fold_strpbrk_past_end(ptr %psub) {
	; CHECK-LABEL: @fold_strpbrk_past_end(
	; CHECK-NEXT: store ptr null, ptr [[PSUB:%.*]], align 8
	; CHECK-NEXT: [[PS50:%.*]] = getelementptr i8, ptr [[PSUB]], i64 8
	; CHECK-NEXT: store ptr null, ptr [[PS50]], align 8
	; CHECK-NEXT: ret void
	;
	%p5 = getelementptr [5 x i8], ptr @a5, i32 0, i32 5

	%s05 = call ptr @strpbrk(ptr @a5, ptr %p5)
	store ptr %s05, ptr %psub

	%s50 = call ptr @strpbrk(ptr %p5, ptr @a5)
	%ps50 = getelementptr ptr, ptr %psub, i32 1
	store ptr %s50, ptr %ps50

	ret void
	}


	; Fold strspn(a5, a5 + 5) (and vice versa) to null.

	define void @fold_strspn_past_end(ptr %poff) {
	; CHECK-LABEL: @fold_strspn_past_end(
	; CHECK-NEXT: store i64 0, ptr [[POFF:%.*]], align 4
	; CHECK-NEXT: [[PO50:%.*]] = getelementptr i8, ptr [[POFF]], i64 8
	; CHECK-NEXT: store i64 0, ptr [[PO50]], align 4
	; CHECK-NEXT: ret void
	;
	%p5 = getelementptr [5 x i8], ptr @a5, i32 0, i32 5

	%o05 = call i64 @strspn(ptr @a5, ptr %p5)
	store i64 %o05, ptr %poff

	%o50 = call i64 @strspn(ptr %p5, ptr @a5)
	%po50 = getelementptr i64, ptr %poff, i32 1
	store i64 %o50, ptr %po50

	ret void
	}


	; Fold strcspn(a5, a5 + 5) (and vice versa) to null.

	define void @fold_strcspn_past_end(ptr %poff) {
	; CHECK-LABEL: @fold_strcspn_past_end(
	; CHECK-NEXT: store i64 2, ptr [[POFF:%.*]], align 4
	; CHECK-NEXT: [[PO50:%.*]] = getelementptr i8, ptr [[POFF]], i64 8
	; CHECK-NEXT: store i64 0, ptr [[PO50]], align 4
	; CHECK-NEXT: ret void
	;
	%p5 = getelementptr [5 x i8], ptr @a5, i32 0, i32 5

	%o05 = call i64 @strcspn(ptr @a5, ptr %p5)
	store i64 %o05, ptr %poff

	%o50 = call i64 @strcspn(ptr %p5, ptr @a5)
	%po50 = getelementptr i64, ptr %poff, i32 1
	store i64 %o50, ptr %po50

	ret void
	}


	; TODO: Fold the 32-bit atoi(a5 + 5) to zero.
	; Verify that processing the invalid call doesn't run into trouble.

	define i32 @fold_atoi_past_end() {
	; CHECK-LABEL: @fold_atoi_past_end(
	; CHECK-NEXT: [[I:%.*]] = call i32 @atoi(ptr nocapture nonnull getelementptr inbounds ([5 x i8], ptr @a5, i64 1, i64 0))
	; CHECK-NEXT: ret i32 [[I]]
	;
	%p5 = getelementptr [5 x i8], ptr @a5, i32 0, i32 5
	%i = call i32 @atoi(ptr %p5)
	ret i32 %i
	}

	; TODO: Likewise, fold the 64-bit atol(a5 + 5) to zero, and similarly
	; for atoll and strtrol and similar.
	; Verify that processing the invalid call doesn't run into trouble.

	define void @fold_atol_strtol_past_end(ptr %ps) {
	; CHECK-LABEL: @fold_atol_strtol_past_end(
	; CHECK-NEXT: [[I0:%.*]] = call i64 @atol(ptr nocapture nonnull getelementptr inbounds ([5 x i8], ptr @a5, i64 1, i64 0))
	; CHECK-NEXT: store i64 [[I0]], ptr [[PS:%.*]], align 4
	; CHECK-NEXT: [[I1:%.*]] = call i64 @atoll(ptr nocapture nonnull getelementptr inbounds ([5 x i8], ptr @a5, i64 1, i64 0))
	; CHECK-NEXT: [[P1:%.*]] = getelementptr i8, ptr [[PS]], i64 8
	; CHECK-NEXT: store i64 [[I1]], ptr [[P1]], align 4
	; CHECK-NEXT: [[I2:%.*]] = call i64 @strtol(ptr nocapture nonnull getelementptr inbounds ([5 x i8], ptr @a5, i64 1, i64 0), ptr null, i32 0)
	; CHECK-NEXT: [[P2:%.*]] = getelementptr i8, ptr [[PS]], i64 16
	; CHECK-NEXT: store i64 [[I2]], ptr [[P2]], align 4
	; CHECK-NEXT: [[I3:%.*]] = call i64 @strtoul(ptr nocapture nonnull getelementptr inbounds ([5 x i8], ptr @a5, i64 1, i64 0), ptr null, i32 8)
	; CHECK-NEXT: [[P3:%.*]] = getelementptr i8, ptr [[PS]], i64 24
	; CHECK-NEXT: store i64 [[I3]], ptr [[P3]], align 4
	; CHECK-NEXT: [[I4:%.*]] = call i64 @strtoll(ptr nocapture nonnull getelementptr inbounds ([5 x i8], ptr @a5, i64 1, i64 0), ptr null, i32 10)
	; CHECK-NEXT: [[P4:%.*]] = getelementptr i8, ptr [[PS]], i64 32
	; CHECK-NEXT: store i64 [[I4]], ptr [[P4]], align 4
	; CHECK-NEXT: [[I5:%.*]] = call i64 @strtoul(ptr nocapture nonnull getelementptr inbounds ([5 x i8], ptr @a5, i64 1, i64 0), ptr null, i32 16)
	; CHECK-NEXT: [[P5:%.*]] = getelementptr i8, ptr [[PS]], i64 40
	; CHECK-NEXT: store i64 [[I5]], ptr [[P5]], align 4
	; CHECK-NEXT: ret void
	;
	%pa5 = getelementptr [5 x i8], ptr @a5, i32 0, i32 5

	%i0 = call i64 @atol(ptr %pa5)
	store i64 %i0, ptr %ps

	%i1 = call i64 @atoll(ptr %pa5)
	%p1 = getelementptr i64, ptr %ps, i32 1
	store i64 %i1, ptr %p1

	%i2 = call i64 @strtol(ptr %pa5, ptr null, i32 0)
	%p2 = getelementptr i64, ptr %ps, i32 2
	store i64 %i2, ptr %p2

	%i3 = call i64 @strtoul(ptr %pa5, ptr null, i32 8)
	%p3 = getelementptr i64, ptr %ps, i32 3
	store i64 %i3, ptr %p3

	%i4 = call i64 @strtoll(ptr %pa5, ptr null, i32 10)
	%p4 = getelementptr i64, ptr %ps, i32 4
	store i64 %i4, ptr %p4

	%i5 = call i64 @strtoul(ptr %pa5, ptr null, i32 16)
	%p5 = getelementptr i64, ptr %ps, i32 5
	store i64 %i5, ptr %p5

	ret void
	}


	; Fold sprintf(dst, a5 + 5) to zero, and also
	; TODO: fold sprintf(dst, "%s", a5 + 5) to zero.

	define void @fold_sprintf_past_end(ptr %pcnt, ptr %dst) {
	; CHECK-LABEL: @fold_sprintf_past_end(
	; CHECK-NEXT: store i32 0, ptr [[PCNT:%.*]], align 4
	; CHECK-NEXT: [[PN05:%.*]] = getelementptr i8, ptr [[PCNT]], i64 4
	; CHECK-NEXT: store i32 0, ptr [[PN05]], align 4
	; CHECK-NEXT: ret void
	;
	%p5 = getelementptr [5 x i8], ptr @a5, i32 0, i32 5

	%n5_ = call i32 (ptr, ptr, ...) @sprintf(ptr %dst, ptr %p5)
	store i32 %n5_, ptr %pcnt

	%n05 = call i32 (ptr, ptr, ...) @sprintf(ptr %dst, ptr @a5, ptr %p5)
	%pn05 = getelementptr i32, ptr %pcnt, i32 1
	store i32 %n05, ptr %pn05

	ret void
	}


	; Fold snprintf(dst, n, a5 + 5) to zero, and also
	; TODO: fold snprintf(dst, n, "%s", a5 + 5) to zero.

	define void @fold_snprintf_past_end(ptr %pcnt, ptr %dst, i64 %n) {
	; CHECK-LABEL: @fold_snprintf_past_end(
	; CHECK-NEXT: [[N5_:%.]] = call i32 (ptr, i64, ptr, ...) @snprintf(ptr [[DST:%.]], i64 [[N:%.*]], ptr nonnull getelementptr inbounds ([5 x i8], ptr @a5, i64 1, i64 0))
	; CHECK-NEXT: store i32 [[N5_]], ptr [[PCNT:%.*]], align 4
	; CHECK-NEXT: [[N05:%.*]] = call i32 (ptr, i64, ptr, ...) @snprintf(ptr [[DST]], i64 [[N]], ptr nonnull @a5, ptr nonnull getelementptr inbounds ([5 x i8], ptr @a5, i64 1, i64 0))
	; CHECK-NEXT: [[PN05:%.*]] = getelementptr i8, ptr [[PCNT]], i64 4
	; CHECK-NEXT: store i32 [[N05]], ptr [[PN05]], align 4
	; CHECK-NEXT: ret void
	;
	%p5 = getelementptr [5 x i8], ptr @a5, i32 0, i32 5

	%n5_ = call i32 (ptr, i64, ptr, ...) @snprintf(ptr %dst, i64 %n, ptr %p5)
	store i32 %n5_, ptr %pcnt

	%n05 = call i32 (ptr, i64, ptr, ...) @snprintf(ptr %dst, i64 %n, ptr @a5, ptr %p5)
	%pn05 = getelementptr i32, ptr %pcnt, i32 1
	store i32 %n05, ptr %pn05

	ret void
	}