llvm-6502/test/CodeGen/X86/jump_sign.ll
Manman Ren 2d4215f759 X86: Fix optimizeCompare to correctly check safe condition.
It is safe if EFLAGS is killed or re-defined.
When we are done with the basic block, check whether EFLAGS is live-out.
Do not optimize away cmp if EFLAGS is live-out.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159888 91177308-0d34-0410-b5e6-96231b3b80d8
2012-07-07 03:34:46 +00:00

176 lines
4.0 KiB
LLVM

; RUN: llc < %s -march=x86 -mcpu=pentiumpro | FileCheck %s
define i32 @f(i32 %X) {
entry:
; CHECK: f:
; CHECK: jns
%tmp1 = add i32 %X, 1 ; <i32> [#uses=1]
%tmp = icmp slt i32 %tmp1, 0 ; <i1> [#uses=1]
br i1 %tmp, label %cond_true, label %cond_next
cond_true: ; preds = %entry
%tmp2 = tail call i32 (...)* @bar( ) ; <i32> [#uses=0]
br label %cond_next
cond_next: ; preds = %cond_true, %entry
%tmp3 = tail call i32 (...)* @baz( ) ; <i32> [#uses=0]
ret i32 undef
}
declare i32 @bar(...)
declare i32 @baz(...)
; rdar://10633221
; rdar://11355268
define i32 @g(i32 %a, i32 %b) nounwind {
entry:
; CHECK: g:
; CHECK-NOT: test
; CHECK: cmovs
%sub = sub nsw i32 %a, %b
%cmp = icmp sgt i32 %sub, 0
%cond = select i1 %cmp, i32 %sub, i32 0
ret i32 %cond
}
; rdar://10734411
define i32 @h(i32 %a, i32 %b) nounwind {
entry:
; CHECK: h:
; CHECK-NOT: cmp
; CHECK: cmov
; CHECK-NOT: movl
; CHECK: ret
%cmp = icmp slt i32 %b, %a
%sub = sub nsw i32 %a, %b
%cond = select i1 %cmp, i32 %sub, i32 0
ret i32 %cond
}
define i32 @i(i32 %a, i32 %b) nounwind {
entry:
; CHECK: i:
; CHECK-NOT: cmp
; CHECK: cmov
; CHECK-NOT: movl
; CHECK: ret
%cmp = icmp sgt i32 %a, %b
%sub = sub nsw i32 %a, %b
%cond = select i1 %cmp, i32 %sub, i32 0
ret i32 %cond
}
define i32 @j(i32 %a, i32 %b) nounwind {
entry:
; CHECK: j:
; CHECK-NOT: cmp
; CHECK: cmov
; CHECK-NOT: movl
; CHECK: ret
%cmp = icmp ugt i32 %a, %b
%sub = sub i32 %a, %b
%cond = select i1 %cmp, i32 %sub, i32 0
ret i32 %cond
}
define i32 @k(i32 %a, i32 %b) nounwind {
entry:
; CHECK: k:
; CHECK-NOT: cmp
; CHECK: cmov
; CHECK-NOT: movl
; CHECK: ret
%cmp = icmp ult i32 %b, %a
%sub = sub i32 %a, %b
%cond = select i1 %cmp, i32 %sub, i32 0
ret i32 %cond
}
; redundant cmp instruction
define i32 @l(i32 %a, i32 %b) nounwind {
entry:
; CHECK: l:
; CHECK-NOT: cmp
%cmp = icmp slt i32 %b, %a
%sub = sub nsw i32 %a, %b
%cond = select i1 %cmp, i32 %sub, i32 %a
ret i32 %cond
}
define i32 @m(i32 %a, i32 %b) nounwind {
entry:
; CHECK: m:
; CHECK-NOT: cmp
%cmp = icmp sgt i32 %a, %b
%sub = sub nsw i32 %a, %b
%cond = select i1 %cmp, i32 %b, i32 %sub
ret i32 %cond
}
; If EFLAGS is live-out, we can't remove cmp if there exists
; a swapped sub.
define i32 @l2(i32 %a, i32 %b) nounwind {
entry:
; CHECK: l2:
; CHECK: cmp
%cmp = icmp eq i32 %b, %a
%sub = sub nsw i32 %a, %b
br i1 %cmp, label %if.then, label %if.else
if.then:
%cmp2 = icmp sgt i32 %b, %a
%sel = select i1 %cmp2, i32 %sub, i32 %a
ret i32 %sel
if.else:
ret i32 %sub
}
; rdar://11540023
define i32 @n(i32 %x, i32 %y) nounwind {
entry:
; CHECK: n:
; CHECK-NOT: sub
; CHECK: cmp
%sub = sub nsw i32 %x, %y
%cmp = icmp slt i32 %sub, 0
%y.x = select i1 %cmp, i32 %y, i32 %x
ret i32 %y.x
}
; PR://13046
define void @o() nounwind uwtable {
entry:
%0 = load i16* undef, align 2
br i1 undef, label %if.then.i, label %if.end.i
if.then.i: ; preds = %entry
unreachable
if.end.i: ; preds = %entry
br i1 undef, label %sw.bb, label %sw.default
sw.bb: ; preds = %if.end.i
br i1 undef, label %if.then44, label %if.end29
if.end29: ; preds = %sw.bb
; CHECK: o:
; CHECK: cmp
%1 = urem i16 %0, 10
%cmp25 = icmp eq i16 %1, 0
%. = select i1 %cmp25, i16 2, i16 0
br i1 %cmp25, label %if.then44, label %sw.default
sw.default: ; preds = %if.end29, %if.end.i
br i1 undef, label %if.then.i96, label %if.else.i97
if.then.i96: ; preds = %sw.default
unreachable
if.else.i97: ; preds = %sw.default
unreachable
if.then44: ; preds = %if.end29, %sw.bb
%aModeRefSel.1.ph = phi i16 [ %., %if.end29 ], [ 3, %sw.bb ]
br i1 undef, label %if.then.i103, label %if.else.i104
if.then.i103: ; preds = %if.then44
unreachable
if.else.i104: ; preds = %if.then44
ret void
}