Add support for using MI bundles as bundle-locked groups on x86

test/NaCl/X86/dynamic-stack-alloc2.ll

Index: test/NaCl/X86/dynamic-stack-alloc2.ll
diff --git a/test/NaCl/X86/dynamic-stack-alloc2.ll b/test/NaCl/X86/dynamic-stack-alloc2.ll
new file mode 100644
index 0000000000000000000000000000000000000000..791a1555d71086ec4454ad56143b75a211571f11
--- /dev/null
+++ b/test/NaCl/X86/dynamic-stack-alloc2.ll
@@ -0,0 +1,31 @@
+; RUN: llc -mtriple=x86_64-nacl %s -o - | FileCheck %s
+
+; CHECK-LABEL: @foo

[jvoung (off chromium), 2015/05/12 23:53:05]

nit: seems better to put this by the function (at least after the "target
datalayout ...; target triple ..." stuff in case more functions are added).

[Derek Schuff, 2015/05/13 00:44:50]

Done.

+; CHECK: .bundle_lock
+; CHECK: leal -16({{.*}}), %esp
+; CHECK: addq %r15, %rsp
+; CHECK: .bundle_unlock
+
+target datalayout = "e-p:32:32-i64:64-n32"
+target triple = "le32-unknown-nacl"
+
+define hidden void @foo(i32 %agg.result, <16 x i8> %v) {

[jvoung (off chromium), 2015/05/12 23:53:05]

The parameters are unused -- is it important for them to be around?

[Derek Schuff, 2015/05/13 00:44:50]

no, removed

+entry:
+  br label %bb1

[jvoung (off chromium), 2015/05/12 23:53:05]

Is it required that the alloca not be in the entry block, or can this be
simplified more? Otherwise, document why?

[Derek Schuff, 2015/05/13 00:44:50]

yes it is required, comment added.

+
+bb1:
+  %0 = alloca i8, i32 16, align 16
+  %.asint = ptrtoint i8* %0 to i32
+  %gep109 = add i32 %.asint, 0

[jvoung (off chromium), 2015/05/12 23:53:05]

Would it be more resilient to optimization have add non-zero?

[Derek Schuff, 2015/05/13 00:44:50]

actually the add isn't necessary at all.

+  %gep109.asptr = inttoptr i32 %gep109 to i8*
+  %1 = load i8, i8* %gep109.asptr, align 1
+  %conv.i = sext i8 %1 to i32
+  %call5 = call i32 @bar(i32 undef, i32 %conv.i)
+  unreachable
+}
+
+
+declare hidden i32 @bar(i32, i32)
+
+

[jvoung (off chromium), 2015/05/12 23:53:05]

extra space

[Derek Schuff, 2015/05/13 00:44:50]

Done.

+