llvm-6502/test/CodeGen/X86/early-ifcvt.ll
Jakob Stoklund Olesen bc70ff3cb9 Handle extra Tail predecessors in if-conversion.
It is still possible to if-convert if the tail block has extra
predecessors, but the tail phis must be rewritten instead of being
removed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161781 91177308-0d34-0410-b5e6-96231b3b80d8
2012-08-13 20:49:04 +00:00

70 lines
1.7 KiB
LLVM

; RUN: llc < %s -enable-early-ifcvt -stress-early-ifcvt | FileCheck %s
target triple = "x86_64-apple-macosx10.8.0"
; CHECK: mm2
define i32 @mm2(i32* nocapture %p, i32 %n) nounwind uwtable readonly ssp {
entry:
br label %do.body
; CHECK: do.body
; Loop body has no branches before the backedge.
; CHECK-NOT: LBB
do.body:
%max.0 = phi i32 [ 0, %entry ], [ %max.1, %do.cond ]
%min.0 = phi i32 [ 0, %entry ], [ %min.1, %do.cond ]
%n.addr.0 = phi i32 [ %n, %entry ], [ %dec, %do.cond ]
%p.addr.0 = phi i32* [ %p, %entry ], [ %incdec.ptr, %do.cond ]
%incdec.ptr = getelementptr inbounds i32* %p.addr.0, i64 1
%0 = load i32* %p.addr.0, align 4
%cmp = icmp sgt i32 %0, %max.0
br i1 %cmp, label %do.cond, label %if.else
if.else:
%cmp1 = icmp slt i32 %0, %min.0
%.min.0 = select i1 %cmp1, i32 %0, i32 %min.0
br label %do.cond
do.cond:
%max.1 = phi i32 [ %0, %do.body ], [ %max.0, %if.else ]
%min.1 = phi i32 [ %min.0, %do.body ], [ %.min.0, %if.else ]
; CHECK: decl %esi
; CHECK: jne LBB
%dec = add i32 %n.addr.0, -1
%tobool = icmp eq i32 %dec, 0
br i1 %tobool, label %do.end, label %do.body
do.end:
%sub = sub nsw i32 %max.1, %min.1
ret i32 %sub
}
; CHECK: multipreds
; Deal with alternative tail predecessors
; CHECK-NOT: LBB
; CHECK: cmov
; CHECK-NOT: LBB
; CHECK: cmov
; CHECK-NOT: LBB
; CHECK: fprintf
define void @multipreds(i32 %sw) nounwind uwtable ssp {
entry:
switch i32 %sw, label %if.then29 [
i32 0, label %if.then37
i32 127, label %if.end41
]
if.then29:
br label %if.end41
if.then37:
br label %if.end41
if.end41:
%exit_status.0 = phi i32 [ 2, %if.then29 ], [ 0, %if.then37 ], [ 66, %entry ]
call void (...)* @fprintf(i32 %exit_status.0) nounwind
unreachable
}
declare void @fprintf(...) nounwind