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llvm-mirror/test/Transforms/NewGVN/2008-07-02-Unreachable.ll
Davide Italiano bd0298b1e1 [GVN] Initial check-in of a new global value numbering algorithm.
The code have been developed by Daniel Berlin over the years, and
the new implementation goal is that of addressing shortcomings of
the current GVN infrastructure, i.e. long compile time for large
testcases, lack of phi predication, no load/store value numbering
etc...

The current code just implements the "core" GVN algorithm, although
other pieces (load coercion, phi handling, predicate system) are
already implemented in a branch out of tree. Once the core is stable,
we'll start adding pieces on top of the base framework.
The test currently living in test/Transform/NewGVN are a copy
of the ones in GVN, with proper `XFAIL` (missing features in NewGVN).
A flag will be added in a future commit to enable NewGVN, so that
interested parties can exercise this code easily.

Differential Revision:  https://reviews.llvm.org/D26224

llvm-svn: 290346
2016-12-22 16:03:48 +00:00

37 lines
768 B
LLVM

; RUN: opt < %s -basicaa -newgvn -S | FileCheck %s
; PR2503
@g_3 = external global i8 ; <i8*> [#uses=2]
define i8 @func_1(i32 %x, i32 %y) nounwind {
entry:
%A = alloca i8
%cmp = icmp eq i32 %x, %y
br i1 %cmp, label %ifelse, label %ifthen
ifthen: ; preds = %entry
br label %ifend
ifelse: ; preds = %entry
%tmp3 = load i8, i8* @g_3 ; <i8> [#uses=0]
store i8 %tmp3, i8* %A
br label %afterfor
forcond: ; preds = %forinc
br i1 false, label %afterfor, label %forbody
forbody: ; preds = %forcond
br label %forinc
forinc: ; preds = %forbody
br label %forcond
afterfor: ; preds = %forcond, %forcond.thread
%tmp10 = load i8, i8* @g_3 ; <i8> [#uses=0]
ret i8 %tmp10
; CHECK: ret i8 %tmp3
ifend: ; preds = %afterfor, %ifthen
ret i8 0
}