llvm-project/llvm/test/Transforms/SimplifyCFG/multiple-phis.ll

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; RUN: opt -simplifycfg -S < %s | FileCheck %s
; It's not worthwhile to if-convert one of the phi nodes and leave
; the other behind, because that still requires a branch. If
; SimplifyCFG if-converts one of the phis, it should do both.
; CHECK: %div.high.addr.0 = select i1 %cmp1, i32 %div, i32 %high.addr.0
; CHECK-NEXT: %low.0.add2 = select i1 %cmp1, i32 %low.0, i32 %add2
; CHECK-NEXT: br label %while.cond
define i32 @upper_bound(i32* %r, i32 %high, i32 %k) nounwind {
entry:
br label %while.cond
while.cond: ; preds = %if.then, %if.else, %entry
%high.addr.0 = phi i32 [ %high, %entry ], [ %div, %if.then ], [ %high.addr.0, %if.else ]
%low.0 = phi i32 [ 0, %entry ], [ %low.0, %if.then ], [ %add2, %if.else ]
%cmp = icmp ult i32 %low.0, %high.addr.0
br i1 %cmp, label %while.body, label %while.end
while.body: ; preds = %while.cond
%add = add i32 %low.0, %high.addr.0
%div = udiv i32 %add, 2
%idxprom = zext i32 %div to i64
%arrayidx = getelementptr inbounds i32* %r, i64 %idxprom
%0 = load i32* %arrayidx
%cmp1 = icmp ult i32 %k, %0
br i1 %cmp1, label %if.then, label %if.else
if.then: ; preds = %while.body
br label %while.cond
if.else: ; preds = %while.body
%add2 = add i32 %div, 1
br label %while.cond
while.end: ; preds = %while.cond
ret i32 %low.0
}