llvm-6502/test/CodeGen/X86/jump_sign.ll
Manman Ren 43d9ab1812 X86 Peephole: fix PR13475 in optimizeCompare.
It is possible that an instruction can use and update EFLAGS.
When checking the safety, we should check the usage of EFLAGS first before
declaring it is safe to optimize due to the update.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160912 91177308-0d34-0410-b5e6-96231b3b80d8
2012-07-28 03:15:46 +00:00

233 lines
5.3 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
}
define i32 @l3(i32 %a, i32 %b) nounwind {
entry:
; CHECK: l3:
; CHECK: sub
; CHECK-NOT: cmp
; CHECK: jge
%cmp = icmp sgt i32 %b, %a
%sub = sub nsw i32 %a, %b
br i1 %cmp, label %if.then, label %if.else
if.then:
ret i32 %sub
if.else:
%add = add nsw i32 %sub, 1
ret i32 %add
}
; rdar://11830760
; When Movr0 is between sub and cmp, we need to move "Movr0" before sub.
define i32 @l4(i32 %a, i32 %b) nounwind {
entry:
; CHECK: l4:
; CHECK: xor
; CHECK: sub
; CHECK-NOT: cmp
%cmp = icmp sgt i32 %b, %a
%sub = sub i32 %a, %b
%.sub = select i1 %cmp, i32 0, i32 %sub
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
}
; rdar://11855129
define i32 @p(i32 %a, i32 %b) nounwind {
entry:
; CHECK: p:
; CHECK-NOT: test
; CHECK: cmovs
%add = add nsw i32 %b, %a
%cmp = icmp sgt i32 %add, 0
%add. = select i1 %cmp, i32 %add, i32 0
ret i32 %add.
}
; PR13475
; If we have sub a, b and cmp b, a and the result of cmp is used
; by sbb, we should not optimize cmp away.
define i32 @q(i32 %j.4, i32 %w, i32 %el) {
; CHECK: q:
; CHECK: sub
; CHECK: cmp
; CHECK-NEXT: sbb
%tmp532 = add i32 %j.4, %w
%tmp533 = icmp ugt i32 %tmp532, %el
%tmp534 = icmp ult i32 %w, %el
%or.cond = and i1 %tmp533, %tmp534
%tmp535 = sub i32 %el, %w
%j.5 = select i1 %or.cond, i32 %tmp535, i32 %j.4
ret i32 %j.5
}