llvm-6502/test/CodeGen/X86/jump_sign.ll
Chandler Carruth d24d326705 [SDAG] Introduce a combined set to the DAG combiner which tracks nodes
which have successfully round-tripped through the combine phase, and use
this to ensure all operands to DAG nodes are visited by the combiner,
even if they are only added during the combine phase.

This is critical to have the combiner reach nodes that are *introduced*
during combining. Previously these would sometimes be visited and
sometimes not be visited based on whether they happened to end up on the
worklist or not. Now we always run them through the combiner.

This fixes quite a few bad codegen test cases lurking in the suite while
also being more principled. Among these, the TLS codegeneration is
particularly exciting for programs that have this in the critical path
like TSan-instrumented binaries (although I think they engineer to use
a different TLS that is faster anyways).

I've tried to check for compile-time regressions here by running llc
over a merged (but not LTO-ed) clang bitcode file and observed at most
a 3% slowdown in llc. Given that this is essentially a worst case (none
of opt or clang are running at this phase) I think this is tolerable.
The actual LTO case should be even less costly, and the cost in normal
compilation should be negligible.

With this combining logic, it is possible to re-legalize as we combine
which is necessary to implement PSHUFB formation on x86 as
a post-legalize DAG combine (my ultimate goal).

Differential Revision: http://reviews.llvm.org/D4638

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213898 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-24 22:15:28 +00:00

308 lines
7.1 KiB
LLVM

; RUN: llc < %s -march=x86 -mcpu=pentiumpro -verify-machineinstrs | FileCheck %s
define i32 @func_f(i32 %X) {
entry:
; CHECK-LABEL: func_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 @func_g(i32 %a, i32 %b) nounwind {
entry:
; CHECK-LABEL: func_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 @func_h(i32 %a, i32 %b) nounwind {
entry:
; CHECK-LABEL: func_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 @func_i(i32 %a, i32 %b) nounwind {
entry:
; CHECK-LABEL: func_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 @func_j(i32 %a, i32 %b) nounwind {
entry:
; CHECK-LABEL: func_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 @func_k(i32 %a, i32 %b) nounwind {
entry:
; CHECK-LABEL: func_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 @func_l(i32 %a, i32 %b) nounwind {
entry:
; CHECK-LABEL: func_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 @func_m(i32 %a, i32 %b) nounwind {
entry:
; CHECK-LABEL: func_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 @func_l2(i32 %a, i32 %b) nounwind {
entry:
; CHECK-LABEL: func_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 @func_l3(i32 %a, i32 %b) nounwind {
entry:
; CHECK-LABEL: func_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 @func_l4(i32 %a, i32 %b) nounwind {
entry:
; CHECK-LABEL: func_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 @func_n(i32 %x, i32 %y) nounwind {
entry:
; CHECK-LABEL: func_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 @func_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-LABEL: func_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 @func_p(i32 %a, i32 %b) nounwind {
entry:
; CHECK-LABEL: func_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 @func_q(i32 %j.4, i32 %w, i32 %el) {
; CHECK-LABEL: func_q:
; 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
}
; rdar://11873276
define i8* @func_r(i8* %base, i32* nocapture %offset, i32 %size) nounwind {
entry:
; CHECK-LABEL: func_r:
; CHECK: sub
; CHECK-NOT: cmp
; CHECK: j
; CHECK-NOT: sub
; CHECK: ret
%0 = load i32* %offset, align 8
%cmp = icmp slt i32 %0, %size
br i1 %cmp, label %return, label %if.end
if.end:
%sub = sub nsw i32 %0, %size
store i32 %sub, i32* %offset, align 8
%add.ptr = getelementptr inbounds i8* %base, i32 %sub
br label %return
return:
%retval.0 = phi i8* [ %add.ptr, %if.end ], [ null, %entry ]
ret i8* %retval.0
}
; Test optimizations of dec/inc.
define i32 @func_dec(i32 %a) nounwind {
entry:
; CHECK-LABEL: func_dec:
; CHECK: decl
; CHECK-NOT: test
; CHECK: cmovsl
%sub = sub nsw i32 %a, 1
%cmp = icmp sgt i32 %sub, 0
%cond = select i1 %cmp, i32 %sub, i32 0
ret i32 %cond
}
define i32 @func_inc(i32 %a) nounwind {
entry:
; CHECK-LABEL: func_inc:
; CHECK: incl
; CHECK-NOT: test
; CHECK: cmovsl
%add = add nsw i32 %a, 1
%cmp = icmp sgt i32 %add, 0
%cond = select i1 %cmp, i32 %add, i32 0
ret i32 %cond
}
; PR13966
@b = common global i32 0, align 4
@a = common global i32 0, align 4
define i32 @func_test1(i32 %p1) nounwind uwtable {
entry:
; CHECK-LABEL: func_test1:
; CHECK: andb
; CHECK: j
; CHECK: ret
%0 = load i32* @b, align 4
%cmp = icmp ult i32 %0, %p1
%conv = zext i1 %cmp to i32
%1 = load i32* @a, align 4
%and = and i32 %conv, %1
%conv1 = trunc i32 %and to i8
%2 = urem i8 %conv1, 3
%tobool = icmp eq i8 %2, 0
br i1 %tobool, label %if.end, label %if.then
if.then:
%dec = add nsw i32 %1, -1
store i32 %dec, i32* @a, align 4
br label %if.end
if.end:
ret i32 undef
}