instcombine: Migrate sprintf optimizations

This patch migrates the sprintf optimizations from the simplify-libcalls
pass into the instcombine library call simplifier.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168677 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 80 insertions, 0 deletions

diff --git a/test/Transforms/InstCombine/sprintf-1.ll b/test/Transforms/InstCombine/sprintf-1.ll
new file mode 100644
index 0000000..1b298b8
--- /dev/null
+++ b/test/Transforms/InstCombine/sprintf-1.ll
@@ -0,0 +1,80 @@
+; 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-prefix=IPRINTF
+
+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"
+@h = constant [2 x i8] c"h\00"
+@percent_c = constant [3 x i8] c"%c\00"
+@percent_d = constant [3 x i8] c"%d\00"
+@percent_f = constant [3 x i8] c"%f\00"
+@percent_s = constant [3 x i8] c"%s\00"
+
+declare i32 @sprintf(i8*, i8*, ...)
+
+; Check sprintf(dst, fmt) -> llvm.memcpy(str, fmt, strlen(fmt) + 1, 1).
+
+define void @test_simplify1(i8* %dst) {
+; CHECK: @test_simplify1
+  %fmt = getelementptr [13 x i8]* @hello_world, i32 0, i32 0
+  call i32 (i8*, i8*, ...)* @sprintf(i8* %dst, i8* %fmt)
+; CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i32(i8* %dst, i8* getelementptr inbounds ([13 x i8]* @hello_world, i32 0, i32 0), i32 13, i32 1, i1 false)
+  ret void
+; CHECK-NEXT: ret void
+}
+
+; Check sprintf(dst, "%c", chr) -> *(i8*)dst = chr; *((i8*)dst + 1) = 0.
+
+define void @test_simplify2(i8* %dst) {
+; CHECK: @test_simplify2
+  %fmt = getelementptr [3 x i8]* @percent_c, i32 0, i32 0
+  call i32 (i8*, i8*, ...)* @sprintf(i8* %dst, i8* %fmt, i8 104)
+; CHECK-NEXT: store i8 104, i8* %dst, align 1
+; CHECK-NEXT: [[NUL:%[a-z0-9]+]] = getelementptr i8* %dst, i32 1
+; CHECK-NEXT: store i8 0, i8* [[NUL]], align 1
+  ret void
+; CHECK-NEXT: ret void
+}
+
+; Check sprintf(dst, "%s", str) -> llvm.memcpy(dest, str, strlen(str) + 1, 1).
+
+define void @test_simplify3(i8* %dst, i8* %str) {
+; CHECK: @test_simplify3
+  %fmt = getelementptr [3 x i8]* @percent_s, i32 0, i32 0
+  call i32 (i8*, i8*, ...)* @sprintf(i8* %dst, i8* %fmt, i8* %str)
+; CHECK-NEXT: [[STRLEN:%[a-z0-9]+]] = call i32 @strlen(i8* %str)
+; CHECK-NEXT: [[LENINC:%[a-z0-9]+]] = add i32 [[STRLEN]], 1
+; CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i32(i8* %dst, i8* %str, i32 [[LENINC]], i32 1, i1 false)
+  ret void
+; CHECK-NEXT: ret void
+}
+
+; Check sprintf(dst, format, ...) -> siprintf(str, format, ...) if no floating.
+
+define void @test_simplify4(i8* %dst) {
+; CHECK-IPRINTF: @test_simplify4
+  %fmt = getelementptr [3 x i8]* @percent_d, i32 0, i32 0
+  call i32 (i8*, i8*, ...)* @sprintf(i8* %dst, i8* %fmt, i32 187)
+; CHECK-NEXT-IPRINTF: call i32 (i8*, i8*, ...)* @siprintf(i8* %dst, i8* getelementptr inbounds ([3 x i8]* @percent_d, i32 0, i32 0), i32 187)
+  ret void
+; CHECK-NEXT-IPRINTF: ret void
+}
+
+define void @test_no_simplify1(i8* %dst) {
+; CHECK-IPRINTF: @test_no_simplify1
+  %fmt = getelementptr [3 x i8]* @percent_f, i32 0, i32 0
+  call i32 (i8*, i8*, ...)* @sprintf(i8* %dst, i8* %fmt, double 1.87)
+; CHECK-NEXT-IPRINTF: call i32 (i8*, i8*, ...)* @sprintf(i8* %dst, i8* getelementptr inbounds ([3 x i8]* @percent_f, i32 0, i32 0), double 1.870000e+00)
+  ret void
+; CHECK-NEXT-IPRINTF: ret void
+}
+
+define void @test_no_simplify2(i8* %dst, i8* %fmt, double %d) {
+; CHECK: @test_no_simplify2
+  call i32 (i8*, i8*, ...)* @sprintf(i8* %dst, i8* %fmt, double %d)
+; CHECK-NEXT: call i32 (i8*, i8*, ...)* @sprintf(i8* %dst, i8* %fmt, double %d)
+  ret void
+; CHECK-NEXT: ret void
+}