Clean up instcombine stpcpy test

[lanza]

Summary

Deduplicate some code and add an additional test to verify that the
sprintf->stpcpy optimization still works on android21 (which properly
supports it).

This follows up 58481663692b55.

[smeenai]

LGTM, thanks!

[srhines]

LGTM from the Android side. Thanks for finding and fixing the original issue, as well as adding this stronger test. :)

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

 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
 ; Test that the sprintf library call simplifier works correctly.
 ;
 ; RUN: opt < %s -instcombine -S | FileCheck %s
-; RUN: opt < %s -mtriple xcore-xmos-elf -instcombine -S | FileCheck %s -check-prefixes=CHECK,CHECK-IPRINTF
+; RUN: opt < %s -mtriple xcore-xmos-elf -instcombine -S | FileCheck %s -check-prefixes=CHECK,CHECK-IPRINTF,WITHSTPCPY
 ; RUN: opt < %s -mtriple=i386-pc-windows-msvc -instcombine -S | FileCheck %s --check-prefixes=CHECK,WIN
-; RUN: opt < %s -mtriple=i386-mingw32 -instcombine -S | FileCheck %s --check-prefixes=CHECK,WIN
-; RUN: opt < %s -mtriple=armv7-none-linux-android16 -instcombine -S | FileCheck %s --check-prefixes=CHECK,ANDROID
+; RUN: opt < %s -mtriple=i386-mingw32 -instcombine -S | FileCheck %s --check-prefixes=CHECK,WIN,NOSTPCPY
+; RUN: opt < %s -mtriple=armv7-none-linux-android16 -instcombine -S | FileCheck %s --check-prefixes=CHECK,NOSTPCPY
+; RUN: opt < %s -mtriple=armv7-none-linux-android21 -instcombine -S | FileCheck %s --check-prefixes=CHECK,WITHSTPCPY
 
 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_world = constant [13 x i8] c"hello world\0A\00"
 @null = constant [1 x i8] zeroinitializer
 @null_hello = constant [7 x i8] c"\00hello\00"
 @h = constant [2 x i8] c"h\00"
 @percent_c = constant [3 x i8] c"%c\00"
;
   %fmt = getelementptr [3 x i8], [3 x i8]* @percent_d, i32 0, i32 0
   call i32 (i8*, i8*, ...) @sprintf(i8* %dst, i8* %fmt, i32 187)
   ret void
 }
 
 ; Check sprintf(dst, "%s", str) -> llvm.memcpy(dest, str, strlen(str) + 1, 1).
 
 define i32 @test_simplify7(i8* %dst, i8* %str) {
-; CHECK-IPRINTF-LABEL: @test_simplify7(
-; CHECK-IPRINTF-NEXT:    [[STPCPY:%.*]] = call i8* @stpcpy(i8* [[DST:%.*]], i8* [[STR:%.*]])
-; CHECK-IPRINTF-NEXT:    [[TMP1:%.*]] = ptrtoint i8* [[STPCPY]] to i32
-; CHECK-IPRINTF-NEXT:    [[TMP2:%.*]] = ptrtoint i8* [[DST]] to i32
-; CHECK-IPRINTF-NEXT:    [[TMP3:%.*]] = sub i32 [[TMP1]], [[TMP2]]
-; CHECK-IPRINTF-NEXT:    ret i32 [[TMP3]]
-;
-; WIN-LABEL: @test_simplify7(
-; WIN-NEXT:    [[STRLEN:%.*]] = call i32 @strlen(i8* noundef nonnull dereferenceable(1) [[STR:%.*]])
-; WIN-NEXT:    [[LENINC:%.*]] = add i32 [[STRLEN]], 1
-; WIN-NEXT:    call void @llvm.memcpy.p0i8.p0i8.i32(i8* align 1 [[DST:%.*]], i8* align 1 [[STR]], i32 [[LENINC]], i1 false)
-; WIN-NEXT:    ret i32 [[STRLEN]]
-;
-; ANDROID-LABEL: @test_simplify7(
-; ANDROID-NEXT:    [[STRLEN:%.*]] = call i32 @strlen(i8* noundef nonnull dereferenceable(1) [[STR:%.*]])
-; ANDROID-NEXT:    [[LENINC:%.*]] = add i32 [[STRLEN]], 1
-; ANDROID-NEXT:    call void @llvm.memcpy.p0i8.p0i8.i32(i8* align 1 [[DST:%.*]], i8* align 1 [[STR]], i32 [[LENINC]], i1 false)
-; ANDROID-NEXT:    ret i32 [[STRLEN]]
+; WITHSTPCPY-LABEL: @test_simplify7(
+; WITHSTPCPY-NEXT:    [[STPCPY:%.*]] = call i8* @stpcpy(i8* [[DST:%.*]], i8* [[STR:%.*]])
+; WITHSTPCPY-NEXT:    [[TMP1:%.*]] = ptrtoint i8* [[STPCPY]] to i32
+; WITHSTPCPY-NEXT:    [[TMP2:%.*]] = ptrtoint i8* [[DST]] to i32
+; WITHSTPCPY-NEXT:    [[TMP3:%.*]] = sub i32 [[TMP1]], [[TMP2]]
+; WITHSTPCPY-NEXT:    ret i32 [[TMP3]]
+;
+; NOSTPCPY-LABEL: @test_simplify7(
+; NOSTPCPY-NEXT:    [[STRLEN:%.*]] = call i32 @strlen(i8* noundef nonnull dereferenceable(1) [[STR:%.*]])
+; NOSTPCPY-NEXT:    [[LENINC:%.*]] = add i32 [[STRLEN]], 1
+; NOSTPCPY-NEXT:    call void @llvm.memcpy.p0i8.p0i8.i32(i8* align 1 [[DST:%.*]], i8* align 1 [[STR]], i32 [[LENINC]], i1 false)
+; NOSTPCPY-NEXT:    ret i32 [[STRLEN]]
 ;
   %fmt = getelementptr [3 x i8], [3 x i8]* @percent_s, i32 0, i32 0
   %r = call i32 (i8*, i8*, ...) @sprintf(i8* %dst, i8* %fmt, i8* %str)
   ret i32 %r
 }
 
 ; Check sprintf(dst, "%s", str) -> llvm.memcpy(dest, str, strlen(str) + 1, 1).
 define i32 @test_simplify8(i8* %dst) {