instcombine: Migrate strchr and strrchr optimizations

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

llvm-svn: 165875

1 files changed, 54 insertions, 0 deletions

diff --git a/llvm/test/Transforms/InstCombine/strchr-1.ll b/llvm/test/Transforms/InstCombine/strchr-1.ll
new file mode 100644
index 00000000000..5efab9ec4be
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/strchr-1.ll
@@ -0,0 +1,54 @@
+; Test that the strchr 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 [14 x i8] c"hello world\5Cn\00"
+@null = constant [1 x i8] zeroinitializer
+@chp = global i8* zeroinitializer
+
+declare i8* @strchr(i8*, i32)
+
+define void @test_simplify1() {
+; CHECK: store i8* getelementptr inbounds ([14 x i8]* @hello, i32 0, i32 6)
+; CHECK-NOT: call i8* @strchr
+; CHECK: ret void
+
+  %str = getelementptr [14 x i8]* @hello, i32 0, i32 0
+  %dst = call i8* @strchr(i8* %str, i32 119)
+  store i8* %dst, i8** @chp
+  ret void
+}
+
+define void @test_simplify2() {
+; CHECK: store i8* null, i8** @chp, align 4
+; CHECK-NOT: call i8* @strchr
+; CHECK: ret void
+
+  %str = getelementptr [1 x i8]* @null, i32 0, i32 0
+  %dst = call i8* @strchr(i8* %str, i32 119)
+  store i8* %dst, i8** @chp
+  ret void
+}
+
+define void @test_simplify3() {
+; CHECK: store i8* getelementptr inbounds ([14 x i8]* @hello, i32 0, i32 13)
+; CHECK-NOT: call i8* @strchr
+; CHECK: ret void
+
+  %src = getelementptr [14 x i8]* @hello, i32 0, i32 0
+  %dst = call i8* @strchr(i8* %src, i32 0)
+  store i8* %dst, i8** @chp
+  ret void
+}
+
+define void @test_simplify4(i32 %chr) {
+; CHECK: call i8* @memchr
+; CHECK-NOT: call i8* @strchr
+; CHECK: ret void
+
+  %src = getelementptr [14 x i8]* @hello, i32 0, i32 0
+  %dst = call i8* @strchr(i8* %src, i32 %chr)
+  store i8* %dst, i8** @chp
+  ret void
+}