instcombine: Migrate strncpy optimizations
This patch migrates the strncpy optimizations from the simplify-libcalls
pass into the instcombine library call simplifier.
llvm-svn: 167102
diff --git a/llvm/test/Transforms/InstCombine/strncpy-1.ll b/llvm/test/Transforms/InstCombine/strncpy-1.ll
new file mode 100644
index 0000000..3ce2b9b
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/strncpy-1.ll
@@ -0,0 +1,95 @@
+; Test that the strncpy library call simplifier works correctly.
+;
+; RUN: opt < %s -instcombine -S | FileCheck %s
+
+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"
+@null = constant [1 x i8] zeroinitializer
+@null_hello = constant [7 x i8] c"\00hello\00"
+@a = common global [32 x i8] zeroinitializer, align 1
+@b = common global [32 x i8] zeroinitializer, align 1
+
+declare i8* @strncpy(i8*, i8*, i32)
+declare i32 @puts(i8*)
+
+; Check a bunch of strncpy invocations together.
+
+define i32 @test_simplify1() {
+; CHECK: @test_simplify1
+; CHECK-NOT: call i8* @strncpy
+; CHECK: call i32 @puts
+ %target = alloca [1024 x i8]
+ %arg1 = getelementptr [1024 x i8]* %target, i32 0, i32 0
+ store i8 0, i8* %arg1
+
+ %arg2 = getelementptr [6 x i8]* @hello, i32 0, i32 0
+ %rslt1 = call i8* @strncpy(i8* %arg1, i8* %arg2, i32 6)
+
+ %arg3 = getelementptr [1 x i8]* @null, i32 0, i32 0
+ %rslt2 = call i8* @strncpy(i8* %rslt1, i8* %arg3, i32 42)
+
+ %arg4 = getelementptr [7 x i8]* @null_hello, i32 0, i32 0
+ %rslt3 = call i8* @strncpy(i8* %rslt2, i8* %arg4, i32 42)
+
+ call i32 @puts( i8* %rslt3 )
+ ret i32 0
+}
+
+; Check strncpy(x, "", y) -> memset(x, '\0', y, 1).
+
+define void @test_simplify2() {
+; CHECK: @test_simplify2
+ %dst = getelementptr [32 x i8]* @a, i32 0, i32 0
+ %src = getelementptr [1 x i8]* @null, i32 0, i32 0
+
+ call i8* @strncpy(i8* %dst, i8* %src, i32 32)
+; CHECK: call void @llvm.memset.p0i8.i32
+ ret void
+}
+
+; Check strncpy(x, y, 0) -> x.
+
+define i8* @test_simplify3() {
+; CHECK: @test_simplify3
+ %dst = getelementptr [32 x i8]* @a, i32 0, i32 0
+ %src = getelementptr [6 x i8]* @hello, i32 0, i32 0
+
+ %ret = call i8* @strncpy(i8* %dst, i8* %src, i32 0)
+ ret i8* %ret
+; CHECK: ret i8* getelementptr inbounds ([32 x i8]* @a, i32 0, i32 0)
+}
+
+; Check strncpy(x, s, c) -> memcpy(x, s, c, 1) [s and c are constant].
+
+define void @test_simplify4() {
+; CHECK: @test_simplify4
+ %dst = getelementptr [32 x i8]* @a, i32 0, i32 0
+ %src = getelementptr [6 x i8]* @hello, i32 0, i32 0
+
+ call i8* @strncpy(i8* %dst, i8* %src, i32 6)
+; CHECK: call void @llvm.memcpy.p0i8.p0i8.i32
+ ret void
+}
+
+; Check cases that shouldn't be simplified.
+
+define void @test_no_simplify1() {
+; CHECK: @test_no_simplify1
+ %dst = getelementptr [32 x i8]* @a, i32 0, i32 0
+ %src = getelementptr [32 x i8]* @b, i32 0, i32 0
+
+ call i8* @strncpy(i8* %dst, i8* %src, i32 32)
+; CHECK: call i8* @strncpy
+ ret void
+}
+
+define void @test_no_simplify2() {
+; CHECK: @test_no_simplify2
+ %dst = getelementptr [32 x i8]* @a, i32 0, i32 0
+ %src = getelementptr [6 x i8]* @hello, i32 0, i32 0
+
+ call i8* @strncpy(i8* %dst, i8* %src, i32 8)
+; CHECK: call i8* @strncpy
+ ret void
+}
diff --git a/llvm/test/Transforms/InstCombine/strncpy-2.ll b/llvm/test/Transforms/InstCombine/strncpy-2.ll
new file mode 100644
index 0000000..ac28ea6
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/strncpy-2.ll
@@ -0,0 +1,22 @@
+; Test that the strncpy library call simplifier works correctly.
+;
+; RUN: opt < %s -instcombine -S | FileCheck %s
+
+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"
+@a = common global [32 x i8] zeroinitializer, align 1
+
+declare i16* @strncpy(i8*, i8*, i32)
+
+; Check that 'strncpy' functions with the wrong prototype aren't simplified.
+
+define void @test_no_simplify1() {
+; CHECK: @test_no_simplify1
+ %dst = getelementptr [32 x i8]* @a, i32 0, i32 0
+ %src = getelementptr [6 x i8]* @hello, i32 0, i32 0
+
+ call i16* @strncpy(i8* %dst, i8* %src, i32 6)
+; CHECK: call i16* @strncpy
+ ret void
+}
diff --git a/llvm/test/Transforms/InstCombine/strncpy_chk-1.ll b/llvm/test/Transforms/InstCombine/strncpy_chk-1.ll
index ae7e2fb..aadff42 100644
--- a/llvm/test/Transforms/InstCombine/strncpy_chk-1.ll
+++ b/llvm/test/Transforms/InstCombine/strncpy_chk-1.ll
@@ -7,27 +7,27 @@
@a = common global [60 x i8] zeroinitializer, align 1
@b = common global [60 x i8] zeroinitializer, align 1
-@.str = private constant [8 x i8] c"abcdefg\00"
+@.str = private constant [12 x i8] c"abcdefghijk\00"
; Check cases where dstlen >= len
define void @test_simplify1() {
; CHECK: @test_simplify1
%dst = getelementptr inbounds [60 x i8]* @a, i32 0, i32 0
- %src = getelementptr inbounds [8 x i8]* @.str, i32 0, i32 0
+ %src = getelementptr inbounds [12 x i8]* @.str, i32 0, i32 0
-; CHECK-NEXT: call i8* @strncpy
- call i8* @__strncpy_chk(i8* %dst, i8* %src, i32 8, i32 60)
+; CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i32
+ call i8* @__strncpy_chk(i8* %dst, i8* %src, i32 12, i32 60)
ret void
}
define void @test_simplify2() {
; CHECK: @test_simplify2
%dst = getelementptr inbounds [60 x i8]* @a, i32 0, i32 0
- %src = getelementptr inbounds [8 x i8]* @.str, i32 0, i32 0
+ %src = getelementptr inbounds [12 x i8]* @.str, i32 0, i32 0
-; CHECK-NEXT: call i8* @strncpy
- call i8* @__strncpy_chk(i8* %dst, i8* %src, i32 8, i32 8)
+; CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i32
+ call i8* @__strncpy_chk(i8* %dst, i8* %src, i32 12, i32 12)
ret void
}
@@ -37,7 +37,7 @@
%src = getelementptr inbounds [60 x i8]* @b, i32 0, i32 0
; CHECK-NEXT: call i8* @strncpy
- call i8* @__strncpy_chk(i8* %dst, i8* %src, i32 8, i32 60)
+ call i8* @__strncpy_chk(i8* %dst, i8* %src, i32 12, i32 60)
ret void
}
@@ -46,7 +46,7 @@
define void @test_no_simplify1() {
; CHECK: @test_no_simplify1
%dst = getelementptr inbounds [60 x i8]* @a, i32 0, i32 0
- %src = getelementptr inbounds [8 x i8]* @.str, i32 0, i32 0
+ %src = getelementptr inbounds [12 x i8]* @.str, i32 0, i32 0
; CHECK-NEXT: call i8* @__strncpy_chk
call i8* @__strncpy_chk(i8* %dst, i8* %src, i32 8, i32 4)
diff --git a/llvm/test/Transforms/SimplifyLibCalls/StrNCpy.ll b/llvm/test/Transforms/SimplifyLibCalls/StrNCpy.ll
deleted file mode 100644
index 4e47b31..0000000
--- a/llvm/test/Transforms/SimplifyLibCalls/StrNCpy.ll
+++ /dev/null
@@ -1,29 +0,0 @@
-; Test that the StrNCpyOptimizer works correctly
-; RUN: opt < %s -simplify-libcalls -S | \
-; RUN: not grep "call.*strncpy"
-
-; This transformation requires the pointer size, as it assumes that size_t is
-; the size of a pointer.
-target datalayout = "-p:64:64:64"
-
-@hello = constant [6 x i8] c"hello\00" ; <[6 x i8]*> [#uses=1]
-@null = constant [1 x i8] zeroinitializer ; <[1 x i8]*> [#uses=1]
-@null_hello = constant [7 x i8] c"\00hello\00" ; <[7 x i8]*> [#uses=1]
-
-declare i8* @strncpy(i8*, i8*, i32)
-
-declare i32 @puts(i8*)
-
-define i32 @main() {
- %target = alloca [1024 x i8] ; <[1024 x i8]*> [#uses=1]
- %arg1 = getelementptr [1024 x i8]* %target, i32 0, i32 0 ; <i8*> [#uses=2]
- store i8 0, i8* %arg1
- %arg2 = getelementptr [6 x i8]* @hello, i32 0, i32 0 ; <i8*> [#uses=1]
- %rslt1 = call i8* @strncpy( i8* %arg1, i8* %arg2, i32 6 ) ; <i8*> [#uses=1]
- %arg3 = getelementptr [1 x i8]* @null, i32 0, i32 0 ; <i8*> [#uses=1]
- %rslt2 = call i8* @strncpy( i8* %rslt1, i8* %arg3, i32 42 ) ; <i8*> [#uses=1]
- %arg4 = getelementptr [7 x i8]* @null_hello, i32 0, i32 0 ; <i8*> [#uses=1]
- %rslt3 = call i8* @strncpy( i8* %rslt2, i8* %arg4, i32 42 ) ; <i8*> [#uses=1]
- call i32 @puts( i8* %rslt3 ) ; <i32>:1 [#uses=0]
- ret i32 0
-}