diff options
author | Sanjay Patel <spatel@rotateright.com> | 2017-12-13 21:58:15 +0000 |
---|---|---|
committer | Sanjay Patel <spatel@rotateright.com> | 2017-12-13 21:58:15 +0000 |
commit | 9a3e5b040137a7bd6b395ba98e6171fd42066bb0 (patch) | |
tree | 18d4e3bafdd2a71638eb29772004304773e92046 /test/Transforms | |
parent | 2b46be6545def38ecf555e22a0031e1f628ce654 (diff) |
[EarlyCSE] recognize commuted and swapped variants of min/max as equivalent (PR35642)
As shown in:
https://bugs.llvm.org/show_bug.cgi?id=35642
...we can have different forms of min/max, so we should recognize those here in EarlyCSE
similar to how we already handle binops and compares that can commute.
Differential Revision: https://reviews.llvm.org/D41136
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@320640 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'test/Transforms')
-rw-r--r-- | test/Transforms/EarlyCSE/commute.ll | 49 |
1 files changed, 27 insertions, 22 deletions
diff --git a/test/Transforms/EarlyCSE/commute.ll b/test/Transforms/EarlyCSE/commute.ll index dcdcdae6465..3adee77ec3d 100644 --- a/test/Transforms/EarlyCSE/commute.ll +++ b/test/Transforms/EarlyCSE/commute.ll @@ -78,8 +78,7 @@ define i8 @smin_commute(i8 %a, i8 %b) { ; CHECK-NEXT: [[CMP1:%.*]] = icmp slt i8 %a, %b ; CHECK-NEXT: [[CMP2:%.*]] = icmp slt i8 %b, %a ; CHECK-NEXT: [[M1:%.*]] = select i1 [[CMP1]], i8 %a, i8 %b -; CHECK-NEXT: [[M2:%.*]] = select i1 [[CMP2]], i8 %b, i8 %a -; CHECK-NEXT: [[R:%.*]] = mul i8 [[M1]], [[M2]] +; CHECK-NEXT: [[R:%.*]] = mul i8 [[M1]], [[M1]] ; CHECK-NEXT: ret i8 [[R]] ; %cmp1 = icmp slt i8 %a, %b @@ -97,9 +96,7 @@ define i1 @smin_swapped(i8 %a, i8 %b) { ; CHECK-NEXT: [[CMP1:%.*]] = icmp sgt i8 %a, %b ; CHECK-NEXT: [[CMP2:%.*]] = icmp slt i8 %a, %b ; CHECK-NEXT: [[M1:%.*]] = select i1 [[CMP1]], i8 %b, i8 %a -; CHECK-NEXT: [[M2:%.*]] = select i1 [[CMP2]], i8 %a, i8 %b -; CHECK-NEXT: [[R:%.*]] = icmp eq i8 [[M2]], [[M1]] -; CHECK-NEXT: ret i1 [[R]] +; CHECK-NEXT: ret i1 true ; %cmp1 = icmp sgt i8 %a, %b %cmp2 = icmp slt i8 %a, %b @@ -114,9 +111,7 @@ define i8 @smax_commute(i8 %a, i8 %b) { ; CHECK-NEXT: [[CMP1:%.*]] = icmp sgt i8 %a, %b ; CHECK-NEXT: [[CMP2:%.*]] = icmp sgt i8 %b, %a ; CHECK-NEXT: [[M1:%.*]] = select i1 [[CMP1]], i8 %a, i8 %b -; CHECK-NEXT: [[M2:%.*]] = select i1 [[CMP2]], i8 %b, i8 %a -; CHECK-NEXT: [[R:%.*]] = urem i8 [[M2]], [[M1]] -; CHECK-NEXT: ret i8 [[R]] +; CHECK-NEXT: ret i8 0 ; %cmp1 = icmp sgt i8 %a, %b %cmp2 = icmp sgt i8 %b, %a @@ -131,9 +126,7 @@ define i8 @smax_swapped(i8 %a, i8 %b) { ; CHECK-NEXT: [[CMP1:%.*]] = icmp slt i8 %a, %b ; CHECK-NEXT: [[CMP2:%.*]] = icmp sgt i8 %a, %b ; CHECK-NEXT: [[M1:%.*]] = select i1 [[CMP1]], i8 %b, i8 %a -; CHECK-NEXT: [[M2:%.*]] = select i1 [[CMP2]], i8 %a, i8 %b -; CHECK-NEXT: [[R:%.*]] = sdiv i8 [[M1]], [[M2]] -; CHECK-NEXT: ret i8 [[R]] +; CHECK-NEXT: ret i8 1 ; %cmp1 = icmp slt i8 %a, %b %cmp2 = icmp sgt i8 %a, %b @@ -148,9 +141,7 @@ define i8 @umin_commute(i8 %a, i8 %b) { ; CHECK-NEXT: [[CMP1:%.*]] = icmp ult i8 %a, %b ; CHECK-NEXT: [[CMP2:%.*]] = icmp ult i8 %b, %a ; CHECK-NEXT: [[M1:%.*]] = select i1 [[CMP1]], i8 %a, i8 %b -; CHECK-NEXT: [[M2:%.*]] = select i1 [[CMP2]], i8 %b, i8 %a -; CHECK-NEXT: [[R:%.*]] = sub i8 [[M2]], [[M1]] -; CHECK-NEXT: ret i8 [[R]] +; CHECK-NEXT: ret i8 0 ; %cmp1 = icmp ult i8 %a, %b %cmp2 = icmp ult i8 %b, %a @@ -167,9 +158,7 @@ define <2 x i8> @umin_swapped(<2 x i8> %a, <2 x i8> %b) { ; CHECK-NEXT: [[CMP1:%.*]] = icmp ugt <2 x i8> %a, %b ; CHECK-NEXT: [[CMP2:%.*]] = icmp ult <2 x i8> %a, %b ; CHECK-NEXT: [[M1:%.*]] = select <2 x i1> [[CMP1]], <2 x i8> %b, <2 x i8> %a -; CHECK-NEXT: [[M2:%.*]] = select <2 x i1> [[CMP2]], <2 x i8> %a, <2 x i8> %b -; CHECK-NEXT: [[R:%.*]] = sub <2 x i8> [[M2]], [[M1]] -; CHECK-NEXT: ret <2 x i8> [[R]] +; CHECK-NEXT: ret <2 x i8> zeroinitializer ; %cmp1 = icmp ugt <2 x i8> %a, %b %cmp2 = icmp ult <2 x i8> %a, %b @@ -184,9 +173,7 @@ define i8 @umax_commute(i8 %a, i8 %b) { ; CHECK-NEXT: [[CMP1:%.*]] = icmp ugt i8 %a, %b ; CHECK-NEXT: [[CMP2:%.*]] = icmp ugt i8 %b, %a ; CHECK-NEXT: [[M1:%.*]] = select i1 [[CMP1]], i8 %a, i8 %b -; CHECK-NEXT: [[M2:%.*]] = select i1 [[CMP2]], i8 %b, i8 %a -; CHECK-NEXT: [[R:%.*]] = udiv i8 [[M1]], [[M2]] -; CHECK-NEXT: ret i8 [[R]] +; CHECK-NEXT: ret i8 1 ; %cmp1 = icmp ugt i8 %a, %b %cmp2 = icmp ugt i8 %b, %a @@ -201,8 +188,7 @@ define i8 @umax_swapped(i8 %a, i8 %b) { ; CHECK-NEXT: [[CMP1:%.*]] = icmp ult i8 %a, %b ; CHECK-NEXT: [[CMP2:%.*]] = icmp ugt i8 %a, %b ; CHECK-NEXT: [[M1:%.*]] = select i1 [[CMP1]], i8 %b, i8 %a -; CHECK-NEXT: [[M2:%.*]] = select i1 [[CMP2]], i8 %a, i8 %b -; CHECK-NEXT: [[R:%.*]] = add i8 [[M2]], [[M1]] +; CHECK-NEXT: [[R:%.*]] = add i8 [[M1]], [[M1]] ; CHECK-NEXT: ret i8 [[R]] ; %cmp1 = icmp ult i8 %a, %b @@ -213,3 +199,22 @@ define i8 @umax_swapped(i8 %a, i8 %b) { ret i8 %r } +; Min/max may exist with non-canonical operands. Value tracking can match those. + +define i8 @smax_nsw(i8 %a, i8 %b) { +; CHECK-LABEL: @smax_nsw( +; CHECK-NEXT: [[SUB:%.*]] = sub nsw i8 %a, %b +; CHECK-NEXT: [[CMP1:%.*]] = icmp slt i8 %a, %b +; CHECK-NEXT: [[CMP2:%.*]] = icmp sgt i8 [[SUB]], 0 +; CHECK-NEXT: [[M1:%.*]] = select i1 [[CMP1]], i8 0, i8 [[SUB]] +; CHECK-NEXT: ret i8 0 +; + %sub = sub nsw i8 %a, %b + %cmp1 = icmp slt i8 %a, %b + %cmp2 = icmp sgt i8 %sub, 0 + %m1 = select i1 %cmp1, i8 0, i8 %sub + %m2 = select i1 %cmp2, i8 %sub, i8 0 + %r = sub i8 %m2, %m1 + ret i8 %r +} + |