1
0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-11-23 19:23:23 +01:00
llvm-mirror/test/Analysis/GlobalsModRef/dead-uses.ll
Eli Friedman 6579a1a109 Make GlobalsAA ignore dead constant expressions.
Slightly improves the precision of GlobalsAA in certain situations, and
makes the behavior of optimization passes more predictable.

Differential Revision: https://reviews.llvm.org/D24104

llvm-svn: 283165
2016-10-04 00:03:55 +00:00

55 lines
1.5 KiB
LLVM

; RUN: opt < %s -instcombine -globals-aa -licm -S | FileCheck %s
; Make sure -globals-aa ignores dead uses of globals.
@a = internal global i32 0, align 4
@c = common global i32 0, align 4
; Function Attrs: nounwind
define i32 @g() {
; Make sure the load of @a is hoisted.
; CHECK-LABEL: define i32 @g()
; CHECK: entry:
; CHECK-NEXT: load i32, i32* @a, align 4
; CHECK-NEXT: br label %for.cond
entry:
br label %for.cond
for.cond: ; preds = %for.inc, %entry
%i.0 = phi i32 [ 0, %entry ], [ %inc, %for.inc ]
%sum.0 = phi i32 [ 0, %entry ], [ %add, %for.inc ]
%cmp = icmp slt i32 %i.0, 1000
br i1 %cmp, label %for.body, label %for.end
for.body: ; preds = %for.cond
%0 = load i32, i32* @a, align 4
%add = add nsw i32 %sum.0, %0
call void @f()
br label %for.inc
for.inc: ; preds = %for.body
%inc = add nsw i32 %i.0, 1
br label %for.cond
for.end: ; preds = %for.cond
ret i32 %sum.0
}
; Function Attrs: nounwind
define internal void @f() {
entry:
%tobool = icmp ne i32 0, 0
br i1 %tobool, label %if.then, label %if.end
if.then: ; preds = %entry
store i32 ptrtoint (i32* @a to i32), i32* @c, align 4
br label %if.end
if.end: ; preds = %if.then, %entry
%0 = load i32, i32* @c, align 4
%inc = add nsw i32 %0, 1
store i32 %inc, i32* @c, align 4
ret void
}