[PATCH] D138899: [DAGCombiner] handle more store value forwarding

[Simon Pilgrim via Phabricator via llvm-commits]

RKSimon added inline comments.


================
Comment at: llvm/test/CodeGen/X86/fastcc-byval.ll:2
 ; RUN: llc < %s -tailcallopt=false | FileCheck %s
-; CHECK: movl 8(%esp), %eax
+; CHECK: movl $1, (%esp)
 ; CHECK: movl 8(%esp), %eax
----------------
RKSimon wrote:
> shchenz wrote:
> > Changing from:
> > ```
> > _bar:                                   ## @bar
> > ## %bb.0:
> > 	subl	$12, %esp
> > 	movl	$1, 8(%esp)
> > 	movl	8(%esp), %eax
> > 	movl	%eax, (%esp)
> > 	calll	_foo
> > 	movl	8(%esp), %eax
> > 	addl	$12, %esp
> > 	retl
> > ```
> > 
> > To:
> > ```
> > _bar:                                   ## @bar
> > ## %bb.0:
> > 	subl	$12, %esp
> > 	movl	$1, 8(%esp)
> > 	movl	$1, (%esp)
> > 	calll	_foo
> > 	movl	8(%esp), %eax
> > 	addl	$12, %esp
> > 	retl
> > ```
> > 
> > Seems one load is saved, needs confirmation from X86 experts.
> Please can you rebase after rG2d63646afdb0e4d8c063fe057916d7900f681968?
Actually, rG51f154b997975ff1001b45823e903f87070222ad


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  https://reviews.llvm.org/D138899/new/

https://reviews.llvm.org/D138899