llvm/test/Transforms/SimplifyCFG/PhiEliminate.ll
Chris Lattner 3aff13b82a - Insert new instructions before DomBlock's terminator,
which is simpler than finding a place to insert in BB.
 - Don't perform the 'if condition hoisting' xform on certain
   i1 PHIs, as it interferes with switch formation.

This re-fixes "example 7", without breaking the world hopefully.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121764 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-14 08:46:09 +00:00

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LLVM

; Test a bunch of cases where the cfg simplification code should
; be able to fold PHI nodes into computation in common cases. Folding the PHI
; nodes away allows the branches to be eliminated, performing a simple form of
; 'if conversion'.
; RUN: opt < %s -simplifycfg -S > %t.xform
; RUN: not grep phi %t.xform
; RUN: grep ret %t.xform
declare void @use(i1)
declare void @use.upgrd.1(i32)
define void @test(i1 %c, i32 %V, i32 %V2) {
; <label>:0
br i1 %c, label %T, label %F
T: ; preds = %0
br label %F
F: ; preds = %T, %0
%B1 = phi i1 [ true, %0 ], [ false, %T ] ; <i1> [#uses=1]
%I6 = phi i32 [ %V, %0 ], [ 0, %T ] ; <i32> [#uses=1]
call void @use( i1 %B1 )
call void @use.upgrd.1( i32 %I6 )
ret void
}