instcombine: Migrate printf optimizations

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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168604 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 120 insertions, 59 deletions

diff --git a/test/Transforms/SimplifyLibCalls/debug-line.ll b/test/Transforms/InstCombine/debug-line.ll
index b668e4b9d3..084efdc989 100644
--- a/test/Transforms/SimplifyLibCalls/debug-line.ll
+++ b/test/Transforms/InstCombine/debug-line.ll
@@ -1,4 +1,4 @@
-; RUN: opt -simplify-libcalls -S < %s | FileCheck %s
+; RUN: opt -instcombine -S < %s | FileCheck %s
 
 
 @.str = private constant [3 x i8] c"%c\00"
diff --git a/test/Transforms/InstCombine/printf-1.ll b/test/Transforms/InstCombine/printf-1.ll
new file mode 100644
index 0000000000..3a910ea437
--- /dev/null
+++ b/test/Transforms/InstCombine/printf-1.ll
@@ -0,0 +1,119 @@
+; Test that the printf 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 = constant [2 x i8] c"%\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 [4 x i8] c"%s\0A\00"
+@empty = constant [1 x i8] c"\00"
+; CHECK: [[STR:@[a-z0-9]+]] = private unnamed_addr constant [12 x i8] c"hello world\00"
+
+declare i32 @printf(i8*, ...)
+
+; Check printf("") -> noop.
+
+define void @test_simplify1() {
+; CHECK: @test_simplify1
+  %fmt = getelementptr [1 x i8]* @empty, i32 0, i32 0
+  call i32 (i8*, ...)* @printf(i8* %fmt)
+  ret void
+; CHECK-NEXT: ret void
+}
+
+; Check printf("x") -> putchar('x'), even for '%'.
+
+define void @test_simplify2() {
+; CHECK: @test_simplify2
+  %fmt = getelementptr [2 x i8]* @h, i32 0, i32 0
+  call i32 (i8*, ...)* @printf(i8* %fmt)
+; CHECK-NEXT: call i32 @putchar(i32 104)
+  ret void
+; CHECK-NEXT: ret void
+}
+
+define void @test_simplify3() {
+; CHECK: @test_simplify3
+  %fmt = getelementptr [2 x i8]* @percent, i32 0, i32 0
+  call i32 (i8*, ...)* @printf(i8* %fmt)
+; CHECK-NEXT: call i32 @putchar(i32 37)
+  ret void
+; CHECK-NEXT: ret void
+}
+
+; Check printf("foo\n") -> puts("foo").
+
+define void @test_simplify4() {
+; CHECK: @test_simplify4
+  %fmt = getelementptr [13 x i8]* @hello_world, i32 0, i32 0
+  call i32 (i8*, ...)* @printf(i8* %fmt)
+; CHECK-NEXT: call i32 @puts(i8* getelementptr inbounds ([12 x i8]* [[STR]], i32 0, i32 0))
+  ret void
+; CHECK-NEXT: ret void
+}
+
+; Check printf("%c", chr) -> putchar(chr).
+
+define void @test_simplify5() {
+; CHECK: @test_simplify5
+  %fmt = getelementptr [3 x i8]* @percent_c, i32 0, i32 0
+  call i32 (i8*, ...)* @printf(i8* %fmt, i8 104)
+; CHECK-NEXT: call i32 @putchar(i32 104)
+  ret void
+; CHECK-NEXT: ret void
+}
+
+; Check printf("%s\n", str) -> puts(str).
+
+define void @test_simplify6() {
+; CHECK: @test_simplify6
+  %fmt = getelementptr [4 x i8]* @percent_s, i32 0, i32 0
+  %str = getelementptr [13 x i8]* @hello_world, i32 0, i32 0
+  call i32 (i8*, ...)* @printf(i8* %fmt, i8* %str)
+; CHECK-NEXT: call i32 @puts(i8* getelementptr inbounds ([13 x i8]* @hello_world, i32 0, i32 0))
+  ret void
+; CHECK-NEXT: ret void
+}
+
+; Check printf(format, ...) -> iprintf(format, ...) if no floating point.
+
+define void @test_simplify7() {
+; CHECK-IPRINTF: @test_simplify7
+  %fmt = getelementptr [3 x i8]* @percent_d, i32 0, i32 0
+  call i32 (i8*, ...)* @printf(i8* %fmt, i32 187)
+; CHECK-NEXT-IPRINTF: call i32 (i8*, ...)* @iprintf(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() {
+; CHECK-IPRINTF: @test_no_simplify1
+  %fmt = getelementptr [3 x i8]* @percent_f, i32 0, i32 0
+  call i32 (i8*, ...)* @printf(i8* %fmt, double 1.87)
+; CHECK-NEXT-IPRINTF: call i32 (i8*, ...)* @printf(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* %fmt, double %d) {
+; CHECK: @test_no_simplify2
+  call i32 (i8*, ...)* @printf(i8* %fmt, double %d)
+; CHECK-NEXT: call i32 (i8*, ...)* @printf(i8* %fmt, double %d)
+  ret void
+; CHECK-NEXT: ret void
+}
+
+define i32 @test_no_simplify3() {
+; CHECK: @test_no_simplify3
+  %fmt = getelementptr [2 x i8]* @h, i32 0, i32 0
+  %ret = call i32 (i8*, ...)* @printf(i8* %fmt)
+; CHECK-NEXT: call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([2 x i8]* @h, i32 0, i32 0))
+  ret i32 %ret
+; CHECK-NEXT: ret i32 %ret
+}
diff --git a/test/Transforms/SimplifyLibCalls/Printf.ll b/test/Transforms/SimplifyLibCalls/Printf.ll
deleted file mode 100644
index 489c993f21..0000000000
--- a/test/Transforms/SimplifyLibCalls/Printf.ll
+++ /dev/null
@@ -1,37 +0,0 @@
-; RUN: opt < %s -simplify-libcalls -S | FileCheck %s
-
-@str = internal constant [13 x i8] c"hello world\0A\00"         ; <[13 x i8]*> [#uses=1]
-@str1 = internal constant [2 x i8] c"h\00"              ; <[2 x i8]*> [#uses=1]
-
-; CHECK: private unnamed_addr constant [12 x i8] c"hello world\00"
-
-declare i32 @printf(i8*, ...)
-
-; CHECK: define void @f0
-; CHECK-NOT: printf
-; CHECK: }
-define void @f0() {
-entry:
-        %tmp1 = tail call i32 (i8*, ...)* @printf( i8* getelementptr ([13 x i8]* @str, i32 0, i32 0) )         ; <i32> [#uses=0]
-        ret void
-}
-
-; CHECK: define void @f1
-; CHECK-NOT: printf
-; CHECK: }
-define void @f1() {
-entry:
-        %tmp1 = tail call i32 (i8*, ...)* @printf( i8* getelementptr ([2 x i8]* @str1, i32 0, i32 0) )         ; <i32> [#uses=0]
-        ret void
-}
-
-; Verify that we don't turn this into a putchar call (thus changing the return
-; value).
-;
-; CHECK: define i32 @f2
-; CHECK: printf
-; CHECK: }
-define i32 @f2() {
-  %call = call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([2 x i8]* @str1, i32 0, i32 0))
-  ret i32 %call
-}
diff --git a/test/Transforms/SimplifyLibCalls/iprintf.ll b/test/Transforms/SimplifyLibCalls/iprintf.ll
index 7f036fe3ab..d6a7074db1 100644
--- a/test/Transforms/SimplifyLibCalls/iprintf.ll
+++ b/test/Transforms/SimplifyLibCalls/iprintf.ll
@@ -6,26 +6,6 @@ target triple = "xcore-xmos-elf"
 @.str = internal constant [4 x i8] c"%f\0A\00"		; <[4 x i8]*> [#uses=1]
 @.str1 = internal constant [4 x i8] c"%d\0A\00"		; <[4 x i8]*> [#uses=1]
 
-; Verify printf with no floating point arguments is transformed to iprintf
-define i32 @f0(i32 %x) nounwind {
-entry:
-; CHECK: define i32 @f0
-; CHECK: @iprintf
-; CHECK: }
-	%0 = tail call i32 (i8*, ...)* @printf(i8* getelementptr ([4 x i8]* @.str1, i32 0, i32 0), i32 %x)		; <i32> [#uses=0]
-	ret i32 %0
-}
-
-; Verify we don't turn this into an iprintf call
-define void @f1(double %x) nounwind {
-entry:
-; CHECK: define void @f1
-; CHECK: @printf
-; CHECK: }
-	%0 = tail call i32 (i8*, ...)* @printf(i8* getelementptr ([4 x i8]* @.str, i32 0, i32 0), double %x) nounwind		; <i32> [#uses=0]
-	ret void
-}
-
 ; Verify sprintf with no floating point arguments is transformed to siprintf
 define i32 @f2(i8* %p, i32 %x) nounwind {
 entry:
@@ -66,6 +46,5 @@ entry:
 	ret i32 %0
 }
 
-declare i32 @printf(i8* nocapture, ...) nounwind
 declare i32 @sprintf(i8* nocapture, i8* nocapture, ...) nounwind
 declare i32 @fprintf(i8* nocapture, i8* nocapture, ...) nounwind