[WebAssembly] Added test for inline assembly roundtrip.

Summary:
Due to previous work to make WebAssembly MC by default stack-only
inline assembly now "just works" (previously it didn't since it had
no way to know types of registers), so no further work required.

So far we only have tests (in inline-asm.ll) which test with
non-existing instructions, so this adds a test that roundtrips
both the inline assembly and its surrounding code thru the assembler.

Reviewers: dschuff, sunfish

Subscribers: sbc100, jgravelle-google, eraman, aheejin, llvm-commits

Differential Revision: https://reviews.llvm.org/D52914

llvm-svn: 344977

1 files changed, 43 insertions, 0 deletions

diff --git a/llvm/test/CodeGen/WebAssembly/inline-asm-roundtrip.ll b/llvm/test/CodeGen/WebAssembly/inline-asm-roundtrip.ll
new file mode 100644
index 00000000000..7fcc3cf276a
--- /dev/null
+++ b/llvm/test/CodeGen/WebAssembly/inline-asm-roundtrip.ll
@@ -0,0 +1,43 @@
+; RUN: llc < %s | llvm-mc -triple=wasm32-unknown-unknown | FileCheck --match-full-lines %s
+
+; Test basic inline assembly can actually be assembled by the assembler.
+
+; .ll code below is the result of this code run thru
+; clang -target wasm32-unknown-unknown-wasm -O2 -S -emit-llvm test.c
+
+; int main(int argc, const char *argv[]) {
+;   int src = 1;
+;   int dst;
+;   asm ("i32.const\t2\n"
+;        "\tget_local\t%1\n"
+;        "\ti32.add\n"
+;        "\tset_local\t%0"
+;        : "=r" (dst)
+;        : "r" (src));
+;   return dst != 3;
+; }
+
+target datalayout = "e-m:e-p:32:32-i64:64-n32:64-S128"
+target triple = "wasm32-unknown-unknown"
+
+; CHECK-LABEL: main:
+; CHECK-NEXT:	.param  	i32, i32
+; CHECK-NEXT:	.local  	i32
+; CHECK-NEXT:	i32.const	1
+; CHECK-NEXT:	set_local	[[SRC:[0-9]+]]
+; CHECK-NEXT:	i32.const	2
+; CHECK-NEXT:	get_local	[[SRC]]
+; CHECK-NEXT:	i32.add
+; CHECK-NEXT:	set_local	[[DST:[0-9]+]]
+; CHECK-NEXT:	get_local	[[DST]]
+; CHECK-NEXT:	i32.const	3
+; CHECK-NEXT:	i32.ne
+
+define i32 @main(i32 %argc, i8** nocapture readnone %argv) #0 {
+entry:
+  %0 = tail call i32 asm "i32.const\092\0A\09get_local\09$1\0A\09i32.add\0A\09set_local\09$0", "=r,r"(i32 1) #1
+  %cmp = icmp ne i32 %0, 3
+  %conv = zext i1 %cmp to i32
+  ret i32 %conv
+}
+