PNaCl: Add NoAlias attributes in ExpandByVal and ExpandVarArgs passes

test/Transforms/NaCl/expand-byval.ll

 ; RUN: opt -expand-byval %s -S | FileCheck %s
 
 target datalayout = "p:32:32:32"
 
 %MyStruct = type { i32, i8, i32 }
 %AlignedStruct = type { double, double }
 
 
 ; Removal of "byval" attribute for passing structs arguments by value
 
 declare void @ext_func(%MyStruct*)
 
 define void @byval_receiver(%MyStruct* byval align 32 %ptr) {
   call void @ext_func(%MyStruct* %ptr)
   ret void
 }
 ; Strip the "byval" and "align" attributes.
-; CHECK: define void @byval_receiver(%MyStruct* %ptr) {
+; CHECK: define void @byval_receiver(%MyStruct* noalias %ptr) {
 ; CHECK-NEXT: call void @ext_func(%MyStruct* %ptr)
 
 
 declare void @ext_byval_func(%MyStruct* byval)
-; CHECK: declare void @ext_byval_func(%MyStruct*)
+; CHECK: declare void @ext_byval_func(%MyStruct* noalias)
 
 define void @byval_caller(%MyStruct* %ptr) {
   call void @ext_byval_func(%MyStruct* byval %ptr)
   ret void
 }
 ; CHECK: define void @byval_caller(%MyStruct* %ptr) {
 ; CHECK-NEXT: %ptr.byval_copy = alloca %MyStruct, align 4
 ; CHECK: call void @llvm.lifetime.start(i64 12, i8* %{{.*}})
 ; CHECK: call void @llvm.memcpy.p0i8.p0i8.i64(i8* %{{.*}}, i8* %{{.*}}, i64 12, i32 0, i1 false)
-; CHECK-NEXT: call void @ext_byval_func(%MyStruct* %ptr.byval_copy)
+; CHECK-NEXT: call void @ext_byval_func(%MyStruct* noalias %ptr.byval_copy)

[jvoung (off chromium), 2013/04/26 19:36:25]

Oh, also doesn't *need* to be in the call here?

[Mark Seaborn, 2013/04/26 19:59:09]

Yes, but as we were discussing it doesn't seem to matter either way for the call
sites.  So I've just done what was simplest in the code and not gone out of my
way to either add or remove "noalias" in calls.

 
 
 define void @byval_tail_caller(%MyStruct* %ptr) {
   tail call void @ext_byval_func(%MyStruct* byval %ptr)
   ret void
 }
 ; CHECK: define void @byval_tail_caller(%MyStruct* %ptr) {
-; CHECK: {{^}} call void @ext_byval_func(%MyStruct* %ptr.byval_copy)
+; CHECK: {{^}} call void @ext_byval_func(%MyStruct* noalias %ptr.byval_copy)
 
 
 define void @byval_invoke(%MyStruct* %ptr) {
   invoke void @ext_byval_func(%MyStruct* byval align 32 %ptr)
       to label %cont unwind label %lpad
 cont:
   ret void
 lpad:
   %lp = landingpad { i8*, i32 } personality i8* null cleanup
   ret void
 }
 ; CHECK: define void @byval_invoke(%MyStruct* %ptr) {
 ; CHECK: %ptr.byval_copy = alloca %MyStruct, align 32
 ; CHECK: call void @llvm.lifetime.start(i64 12, i8* %{{.*}})
-; CHECK: invoke void @ext_byval_func(%MyStruct* %ptr.byval_copy)
+; CHECK: invoke void @ext_byval_func(%MyStruct* noalias %ptr.byval_copy)
 ; CHECK: cont:
 ; CHECK: call void @llvm.lifetime.end(i64 12, i8* %{{.*}})
 ; CHECK: lpad:
 ; CHECK: call void @llvm.lifetime.end(i64 12, i8* %{{.*}})
 
 
 ; Check handling of alignment
 
 ; Check that "align" is stripped for declarations too.
 declare void @ext_byval_func_align(%MyStruct* byval align 32)
-; CHECK: declare void @ext_byval_func_align(%MyStruct*)
+; CHECK: declare void @ext_byval_func_align(%MyStruct* noalias)
 
 define void @byval_caller_align_via_attr(%MyStruct* %ptr) {
   call void @ext_byval_func(%MyStruct* byval align 32 %ptr)
   ret void
 }
 ; CHECK: define void @byval_caller_align_via_attr(%MyStruct* %ptr) {
 ; CHECK-NEXT: %ptr.byval_copy = alloca %MyStruct, align 32
 ; The memcpy may assume that %ptr is 32-byte-aligned.
 ; CHECK: call void @llvm.memcpy.p0i8.p0i8.i64(i8* %2, i8* %3, i64 12, i32 32, i1 false)
 
@@ skipping 36 matching lines @@
 define void @inreg_attr(%MyStruct* inreg %ptr) {
   ret void
 }
 ; CHECK: define void @inreg_attr(%MyStruct* inreg %ptr) {
 
 declare void @func_attrs() #0
 ; CHECK: declare void @func_attrs() #0
 
 attributes #0 = { noreturn nounwind }
 ; CHECK: attributes #0 = { noreturn nounwind }