llvm-6502/test/Transforms/IndVarSimplify/2003-09-23-NotAtTop.ll
Dan Gohman 4d8414f420 Teach SCEVExpander's visitAddRecExpr to reuse an existing canonical
induction variable when the addrec to be expanded does not require
a wider type. This eliminates the need for IndVarSimplify to
micro-manage SCEV expansions, because SCEVExpander now
automatically expands them in the form that IndVarSimplify considers
to be canonical. (LSR still micro-manages its SCEV expansions,
because it's optimizing for the target, rather than for
other optimizations.)

Also, this uses the new getAnyExtendExpr, which has more clever
expression simplification logic than the IndVarSimplify code it
replaces, and this cleans up some ugly expansions in code such as
the included masked-iv.ll testcase.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73294 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-13 16:25:49 +00:00

19 lines
695 B
LLVM

; RUN: llvm-as < %s | opt -indvars | llvm-dis | %prcontext ^Loop: 1 | grep %Canonical
; The indvar simplification code should ensure that the first PHI in the block
; is the canonical one!
define i32 @test() {
; <label>:0
br label %Loop
Loop: ; preds = %Loop, %0
%NonIndvar = phi i32 [ 200, %0 ], [ %NonIndvarNext, %Loop ] ; <i32> [#uses=1]
%Canonical = phi i32 [ 0, %0 ], [ %CanonicalNext, %Loop ] ; <i32> [#uses=2]
store i32 %Canonical, i32* null
%NonIndvarNext = sdiv i32 %NonIndvar, 2 ; <i32> [#uses=1]
%CanonicalNext = add i32 %Canonical, 1 ; <i32> [#uses=1]
br label %Loop
}