llvm/test/CodeGen/Lanai/sub-cmp-peephole.ll
Jacques Pienaar 261c94d576 [lanai] Use peephole optimizer to generate more conditional ALU operations.
Summary:
* Similiar to the ARM backend yse the peephole optimizer to generate more conditional ALU operations;
* Add predicated type with default always true to RR instructions in LanaiInstrInfo.td;
* Move LanaiSetflagAluCombiner into optimizeCompare;
* The ASM parser can currently only handle explicitly specified CC, so specify ".t" (true) where needed in the ASM test;
* Remove unused MachineOperand flags;

Reviewers: eliben

Subscribers: aemerson

Differential Revision: http://reviews.llvm.org/D22072

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@274807 91177308-0d34-0410-b5e6-96231b3b80d8
2016-07-07 23:36:04 +00:00

110 lines
2.6 KiB
LLVM

; RUN: llc < %s -mtriple=lanai | FileCheck %s
define i32 @f(i32 inreg %a, i32 inreg %b) nounwind ssp {
entry:
; CHECK-LABEL: f:
; CHECK: sub.f %r6, %r7, [[IN:%.*]]
; CHECK: sel.gt [[IN]], %r0, %rv
%cmp = icmp sgt i32 %a, %b
%sub = sub nsw i32 %a, %b
%sub. = select i1 %cmp, i32 %sub, i32 0
ret i32 %sub.
}
define i32 @g(i32 inreg %a, i32 inreg %b) nounwind ssp {
entry:
; CHECK-LABEL: g:
; CHECK: sub.f %r7, %r6, [[IN:%.*]]
; CHECK: sel.lt [[IN]], %r0, %rv
%cmp = icmp slt i32 %a, %b
%sub = sub nsw i32 %b, %a
%sub. = select i1 %cmp, i32 %sub, i32 0
ret i32 %sub.
}
define i32 @h(i32 inreg %a, i32 inreg %b) nounwind ssp {
entry:
; CHECK-LABEL: h:
; CHECK: sub.f %r6, 0x3, [[IN:%.*]]
; CHECK: sel.gt [[IN]], %r7, %rv
%cmp = icmp sgt i32 %a, 3
%sub = sub nsw i32 %a, 3
%sub. = select i1 %cmp, i32 %sub, i32 %b
ret i32 %sub.
}
define i32 @i(i32 inreg %a, i32 inreg %b) nounwind readnone ssp {
entry:
; CHECK-LABEL: i:
; CHECK: sub.f %r7, %r6, [[IN:%.*]]
; CHECK: sel.ult [[IN]], %r0, %rv
%cmp = icmp ult i32 %a, %b
%sub = sub i32 %b, %a
%sub. = select i1 %cmp, i32 %sub, i32 0
ret i32 %sub.
}
; If SR is live-out, we can't remove cmp if there exists a swapped sub.
define i32 @j(i32 inreg %a, i32 inreg %b) nounwind {
entry:
; CHECK-LABEL: j:
; CHECK: sub.f %r7, %r6, %r0
; CHECK: sub %r6, %r7, %rv
%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
}
declare void @abort()
declare void @exit(i32)
@t = common global i32 0
; If the comparison uses the C bit (signed overflow/underflow), we can't
; omit the comparison.
define i32 @cmp_ult0(i32 inreg %a, i32 inreg %b, i32 inreg %x, i32 inreg %y) {
entry:
; CHECK-LABEL: cmp_ult0
; CHECK: sub {{.*}}, 0x11, [[IN:%.*]]
; CHECK: sub.f [[IN]], 0x0, %r0
%load = load i32, i32* @t, align 4
%sub = sub i32 %load, 17
%cmp = icmp ult i32 %sub, 0
br i1 %cmp, label %if.then, label %if.else
if.then:
call void @abort()
unreachable
if.else:
call void @exit(i32 0)
unreachable
}
; Same for the V bit.
; TODO: add test that exercises V bit individually (VC/VS).
define i32 @cmp_gt0(i32 inreg %a, i32 inreg %b, i32 inreg %x, i32 inreg %y) {
entry:
; CHECK-LABEL: cmp_gt0
; CHECK: sub {{.*}}, 0x11, [[IN:%.*]]
; CHECK: sub.f [[IN]], 0x1, %r0
%load = load i32, i32* @t, align 4
%sub = sub i32 %load, 17
%cmp = icmp sgt i32 %sub, 0
br i1 %cmp, label %if.then, label %if.else
if.then:
call void @abort()
unreachable
if.else:
call void @exit(i32 0)
unreachable
}