PNaCl: Add NoAlias attributes in ExpandByVal and ExpandVarArgs passes

test/Transforms/NaCl/expand-varargs.ll

 ; RUN: opt < %s -expand-varargs -S | FileCheck %s
 
 %va_list = type i8*
 
 declare void @llvm.va_start(i8*)
 declare void @llvm.va_end(i8*)
 declare void @llvm.va_copy(i8*, i8*)
 
 declare i32 @outside_func(i32 %arg, %va_list* %args)
 
 
 ; Produced by the expansion of @varargs_call1():
 ; CHECK: %vararg_call = type <{ i64, i32 }>
 
 ; Produced by the expansion of @call_with_zero_varargs().
 ; We have a dummy field to deal with buggy programs:
 ; CHECK: %vararg_call.0 = type <{ i32 }>
 
 
 define i32 @varargs_func(i32 %arg, ...) {
   %arglist_alloc = alloca %va_list
   %arglist = bitcast %va_list* %arglist_alloc to i8*
 
   call void @llvm.va_start(i8* %arglist)
   %result = call i32 @outside_func(i32 %arg, %va_list* %arglist_alloc)
   call void @llvm.va_end(i8* %arglist)
   ret i32 %result
 }
 ; CHECK: define i32 @varargs_func(i32 %arg, i8* %varargs) {

[jvoung (off chromium), 2013/04/26 16:43:09]

Same question about noalias for the new %varargs param

[Mark Seaborn, 2013/04/26 16:52:58]

Done.

 ; CHECK-NEXT: %arglist_alloc = alloca i8*
 ; CHECK-NEXT: %arglist = bitcast i8** %arglist_alloc to i8*
 ; CHECK-NEXT: %arglist1 = bitcast i8* %arglist to i8**
 ; CHECK-NEXT: store i8* %varargs, i8** %arglist1
 ; CHECK-NEXT: %result = call i32 @outside_func(i32 %arg, i8** %arglist_alloc)
 ; CHECK-NEXT: ret i32 %result
 
 
 define i32 @varargs_call1() {
   %result = call i32 (i32, ...)* @varargs_func(i32 111, i64 222, i32 333)
   ret i32 %result
 }
 ; CHECK: define i32 @varargs_call1() {
 ; CHECK-NEXT: %vararg_buffer = alloca %vararg_call
 ; CHECK-NEXT: %vararg_lifetime_bitcast = bitcast %vararg_call* %vararg_buffer to i8*
 ; CHECK-NEXT: call void @llvm.lifetime.start(i64 12, i8* %vararg_lifetime_bitcast)
 ; CHECK-NEXT: %vararg_ptr = getelementptr %vararg_call* %vararg_buffer, i32 0, i32 0
 ; CHECK-NEXT: store i64 222, i64* %vararg_ptr
 ; CHECK-NEXT: %vararg_ptr1 = getelementptr %vararg_call* %vararg_buffer, i32 0, i32 1
 ; CHECK-NEXT: store i32 333, i32* %vararg_ptr1
 ; CHECK-NEXT: %vararg_func = bitcast i32 (i32, ...)* bitcast (i32 (i32, i8*)* @varargs_func to i32 (i32, ...)*) to i32 (i32, %vararg_call*)*
-; CHECK-NEXT: %result = call i32 %vararg_func(i32 111, %vararg_call* %vararg_buffer)
+; CHECK-NEXT: %result = call i32 %vararg_func(i32 111, %vararg_call* noalias %vararg_buffer)
 ; CHECK-NEXT: call void @llvm.lifetime.end(i64 12, i8* %vararg_lifetime_bitcast)
 ; CHECK-NEXT: ret i32 %result
 
 
 ; Check that the pass works when there are no variable arguments.
 define i32 @call_with_zero_varargs() {
   %result = call i32 (i32, ...)* @varargs_func(i32 111)
   ret i32 %result
 }
 ; CHECK: define i32 @call_with_zero_varargs() {
 ; CHECK-NEXT: %vararg_buffer = alloca %vararg_call.0
 ; CHECK: %vararg_func = bitcast i32 (i32, ...)* bitcast (i32 (i32, i8*)* @varargs_func to i32 (i32, ...)*) to i32 (i32, %vararg_call.0*)*
-; CHECK-NEXT: %result = call i32 %vararg_func(i32 111, %vararg_call.0* %vararg_buffer)
+; CHECK-NEXT: %result = call i32 %vararg_func(i32 111, %vararg_call.0* noalias %vararg_buffer)
 
 
 ; Check that "invoke" instructions are expanded out too.
 define i32 @varargs_invoke() {
   %result = invoke i32 (i32, ...)* @varargs_func(i32 111, i64 222)
       to label %cont unwind label %lpad
 cont:
   ret i32 %result
 lpad:
   %lp = landingpad { i8*, i32 } personality i8* null cleanup
   ret i32 0
 }
 ; CHECK: @varargs_invoke
-; CHECK: %result = invoke i32 %vararg_func(i32 111, %vararg_call.1* %vararg_buffer)
+; CHECK: %result = invoke i32 %vararg_func(i32 111, %vararg_call.1* noalias %vararg_buffer)
 ; CHECK-NEXT: to label %cont unwind label %lpad
 ; CHECK: cont:
 ; CHECK-NEXT: call void @llvm.lifetime.end(i64 8, i8* %vararg_lifetime_bitcast)
 ; CHECK: lpad:
 ; CHECK: call void @llvm.lifetime.end(i64 8, i8* %vararg_lifetime_bitcast)
 
 
 define void @varargs_multiple_calls() {
   %call1 = call i32 (i32, ...)* @varargs_func(i32 11, i64 22, i32 33)
   %call2 = call i32 (i32, ...)* @varargs_func(i32 44, i64 55, i32 66)
   ret void
 }
 ; CHECK: @varargs_multiple_calls()
 ; The added allocas should appear at the start of the function.
 ; CHECK: %vararg_buffer{{.*}} = alloca %vararg_call{{.*}}
 ; CHECK: %vararg_buffer{{.*}} = alloca %vararg_call{{.*}}
-; CHECK: %call1 = call i32 %vararg_func{{.*}}(i32 11, %vararg_call{{.*}}* %vararg_buffer{{.*}})
-; CHECK: %call2 = call i32 %vararg_func{{.*}}(i32 44, %vararg_call{{.*}}* %vararg_buffer{{.*}})
+; CHECK: %call1 = call i32 %vararg_func{{.*}}(i32 11, %vararg_call{{.*}}* noalias %vararg_buffer{{.*}})
+; CHECK: %call2 = call i32 %vararg_func{{.*}}(i32 44, %vararg_call{{.*}}* noalias %vararg_buffer{{.*}})
 
 
 define i32 @va_arg_i32(i8* %arglist) {
   %result = va_arg i8* %arglist, i32
   ret i32 %result
 }
 ; CHECK: define i32 @va_arg_i32(i8* %arglist) {
 ; CHECK-NEXT: %arglist1 = bitcast i8* %arglist to i32**
 ; CHECK-NEXT: %arglist_current = load i32** %arglist1
 ; CHECK-NEXT: %result = load i32* %arglist_current
@@ skipping 18 matching lines @@
 define void @do_va_copy(i8* %dest, i8* %src) {
   call void @llvm.va_copy(i8* %dest, i8* %src)
   ret void
 }
 ; CHECK: define void @do_va_copy(i8* %dest, i8* %src) {
 ; CHECK-NEXT: %vacopy_src = bitcast i8* %src to i8**
 ; CHECK-NEXT: %vacopy_dest = bitcast i8* %dest to i8**
 ; CHECK-NEXT: %vacopy_currentptr = load i8** %vacopy_src
 ; CHECK-NEXT: store i8* %vacopy_currentptr, i8** %vacopy_dest
 ; CHECK-NEXT: ret void