[WebAssembly] Optimize memcpy/memmove/memcpy calls.

These calls return their first argument, but because LLVM uses an intrinsic
with a void return type, they can't use the returned attribute. Generalize
the store results pass to optimize these calls too.

llvm-svn: 258781

1 files changed, 60 insertions, 0 deletions

diff --git a/llvm/test/CodeGen/WebAssembly/mem-intrinsics.ll b/llvm/test/CodeGen/WebAssembly/mem-intrinsics.ll
new file mode 100644
index 00000000000..ba2f1e702af
--- /dev/null
+++ b/llvm/test/CodeGen/WebAssembly/mem-intrinsics.ll
@@ -0,0 +1,60 @@
+; RUN: llc < %s -asm-verbose=false | FileCheck %s
+
+; Test memcpy, memmove, and memset intrinsics.
+
+target datalayout = "e-m:e-p:32:32-i64:64-n32:64-S128"
+target triple = "wasm32-unknown-unknown"
+
+declare void @llvm.memcpy.p0i8.p0i8.i32(i8* nocapture, i8* nocapture readonly, i32, i32, i1)
+declare void @llvm.memmove.p0i8.p0i8.i32(i8* nocapture, i8* nocapture readonly, i32, i32, i1)
+declare void @llvm.memset.p0i8.i32(i8* nocapture, i8, i32, i32, i1)
+
+; Test that return values are optimized.
+
+; CHECK-LABEL: copy_yes:
+; CHECK:      i32.call $push0=, memcpy@FUNCTION, $0, $1, $2{{$}}
+; CHECK-NEXT: return   $pop0{{$}}
+define i8* @copy_yes(i8* %dst, i8* %src, i32 %len) {
+  call void @llvm.memcpy.p0i8.p0i8.i32(i8* %dst, i8* %src, i32 %len, i32 1, i1 false)
+  ret i8* %dst
+}
+
+; CHECK-LABEL: copy_no:
+; CHECK:      i32.call $discard=, memcpy@FUNCTION, $0, $1, $2{{$}}
+; CHECK-NEXT: return{{$}}
+define void @copy_no(i8* %dst, i8* %src, i32 %len) {
+  call void @llvm.memcpy.p0i8.p0i8.i32(i8* %dst, i8* %src, i32 %len, i32 1, i1 false)
+  ret void
+}
+
+; CHECK-LABEL: move_yes:
+; CHECK:      i32.call $push0=, memmove@FUNCTION, $0, $1, $2{{$}}
+; CHECK-NEXT: return   $pop0{{$}}
+define i8* @move_yes(i8* %dst, i8* %src, i32 %len) {
+  call void @llvm.memmove.p0i8.p0i8.i32(i8* %dst, i8* %src, i32 %len, i32 1, i1 false)
+  ret i8* %dst
+}
+
+; CHECK-LABEL: move_no:
+; CHECK:      i32.call $discard=, memmove@FUNCTION, $0, $1, $2{{$}}
+; CHECK-NEXT: return{{$}}
+define void @move_no(i8* %dst, i8* %src, i32 %len) {
+  call void @llvm.memmove.p0i8.p0i8.i32(i8* %dst, i8* %src, i32 %len, i32 1, i1 false)
+  ret void
+}
+
+; CHECK-LABEL: set_yes:
+; CHECK:      i32.call $push0=, memset@FUNCTION, $0, $1, $2{{$}}
+; CHECK-NEXT: return   $pop0{{$}}
+define i8* @set_yes(i8* %dst, i8 %src, i32 %len) {
+  call void @llvm.memset.p0i8.i32(i8* %dst, i8 %src, i32 %len, i32 1, i1 false)
+  ret i8* %dst
+}
+
+; CHECK-LABEL: set_no:
+; CHECK:      i32.call $discard=, memset@FUNCTION, $0, $1, $2{{$}}
+; CHECK-NEXT: return{{$}}
+define void @set_no(i8* %dst, i8 %src, i32 %len) {
+  call void @llvm.memset.p0i8.i32(i8* %dst, i8 %src, i32 %len, i32 1, i1 false)
+  ret void
+}