replica
/
hanchenye-llvm-project
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

implement PR2328. 

llvm-svn: 51176
This commit is contained in:
Chris Lattner 2008-05-16 02:59:42 +00:00
parent 0bf92b14f1
commit 5c953b7d27
2 changed files with 16 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
llvm/lib/Transforms/Scalar/InstructionCombining.cpp
View File

@ -3012,6 +3012,10 @@ Instruction *InstCombiner::commonDivTransforms(BinaryOperator &I) {
Instruction *InstCombiner::commonIDivTransforms(BinaryOperator &I) {
Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
// (sdiv X, X) --> 1 (udiv X, X) --> 1
if (Op0 == Op1)
return ReplaceInstUsesWith(I, ConstantInt::get(I.getType(), 1));
if (Instruction *Common = commonDivTransforms(I))
return Common;

14
llvm/test/Transforms/InstCombine/div.ll
View File

@ -1,8 +1,6 @@
; This test makes sure that div instructions are properly eliminated.
;
; RUN: llvm-as < %s | opt -instcombine | llvm-dis | not grep div
; END.
define i32 @test1(i32 %A) {
%B = sdiv i32 %A, 1 ; <i32> [#uses=1]
@ -72,3 +70,15 @@ define i32 @test11(i32 %X, i1 %C) {
%B = udiv i32 %X, %A ; <i32> [#uses=1]
ret i32 %B
}
; PR2328
define i32 @test12(i32 %x) nounwind {
%tmp3 = udiv i32 %x, %x ; 1
ret i32 %tmp3
}
define i32 @test13(i32 %x) nounwind {
%tmp3 = sdiv i32 %x, %x ; 1
ret i32 %tmp3
}