Mercurial > hg > CbC > CbC_llvm
view test/Transforms/InstCombine/constant-fold-alias.ll @ 95:afa8332a0e37 LLVM3.8
LLVM 3.8
author | Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> |
---|---|
date | Tue, 13 Oct 2015 17:48:58 +0900 |
parents | 60c9769439b8 |
children |
line wrap: on
line source
; RUN: opt -S < %s -instcombine | FileCheck %s target datalayout = "e-p1:16:16-p2:32:32-p3:64:64" @G1 = global i32 42, align 1 @G2 = global i32 42 @G3 = global [4 x i8] zeroinitializer, align 1 @A1 = alias i32, bitcast (i8* getelementptr inbounds ([4 x i8], [4 x i8]* @G3, i32 0, i32 2) to i32*) @A2 = alias i32, inttoptr (i64 and (i64 ptrtoint (i8* getelementptr inbounds ([4 x i8], [4 x i8]* @G3, i32 0, i32 3) to i64), i64 -4) to i32*) define i64 @f1() { ; This cannot be constant folded because G1 is underaligned. ; CHECK-LABEL: @f1( ; CHECK: ret i64 and ret i64 and (i64 ptrtoint (i32* @G1 to i64), i64 1) } define i64 @f2() { ; The preferred alignment for G2 allows this one to foled to zero. ; CHECK-LABEL: @f2( ; CHECK: ret i64 0 ret i64 and (i64 ptrtoint (i32* @G2 to i64), i64 1) } define i64 @g1() { ; This cannot be constant folded because A1 aliases G3 which is underalaigned. ; CHECK-LABEL: @g1( ; CHECK: ret i64 and ret i64 and (i64 ptrtoint (i32* @A1 to i64), i64 1) } define i64 @g2() { ; While A2 also aliases G3 which is underaligned, the math of A2 forces a ; certain alignment allowing this to fold to zero. ; CHECK-LABEL: @g2( ; CHECK: ret i64 0 ret i64 and (i64 ptrtoint (i32* @A2 to i64), i64 1) }