Author: Sanjay Patel Date: 2020-03-19T10:02:25+01:00 New Revision: cfa792458fc47f9890d94a2718288c269c8a2a6e
URL: https://github.com/llvm/llvm-project/commit/cfa792458fc47f9890d94a2718288c269c8a2a6e DIFF: https://github.com/llvm/llvm-project/commit/cfa792458fc47f9890d94a2718288c269c8a2a6e.diff LOG: [Transforms] add phase ordering tests for min/max/abs; NFC Test that instcombine and early-cse can cooperate to reduce sequences of select patterns that are not composed of the same underlying instructions. There's a bug in EarlyCSE (PR41083), and we can test how much a possible fix (D74285) may affect optimization. (cherry picked from commit 0ad6e726ec7eee8ef14a89fa288d5a1420d96b1e) Added: llvm/test/Transforms/PhaseOrdering/min-max-abs-cse.ll Modified: Removed: ################################################################################ diff --git a/llvm/test/Transforms/PhaseOrdering/min-max-abs-cse.ll b/llvm/test/Transforms/PhaseOrdering/min-max-abs-cse.ll new file mode 100644 index 000000000000..fcdbbbf3d128 --- /dev/null +++ b/llvm/test/Transforms/PhaseOrdering/min-max-abs-cse.ll @@ -0,0 +1,87 @@ +; NOTE: Assertions have been autogenerated by utils/update_test_checks.py +; RUN: opt < %s -S -O1 | FileCheck %s +; RUN: opt -passes='default<O1>' -S < %s | FileCheck %s + +; In all tests, expect instcombine to canonicalize the select patterns +; for min/max/abs to allow CSE and subsequent simplification. + +; sub (smax a,b), (smax a,b) --> 0 + +define i8 @smax_nsw(i8 %a, i8 %b) { +; CHECK-LABEL: @smax_nsw( +; 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 +} + +; or (abs a), (abs a) --> abs a + +define i8 @abs_swapped(i8 %a) { +; CHECK-LABEL: @abs_swapped( +; CHECK-NEXT: [[NEG:%.*]] = sub i8 0, [[A:%.*]] +; CHECK-NEXT: [[CMP1:%.*]] = icmp slt i8 [[A]], 0 +; CHECK-NEXT: [[M1:%.*]] = select i1 [[CMP1]], i8 [[NEG]], i8 [[A]] +; CHECK-NEXT: ret i8 [[M1]] +; + %neg = sub i8 0, %a + %cmp1 = icmp sgt i8 %a, 0 + %cmp2 = icmp slt i8 %a, 0 + %m1 = select i1 %cmp1, i8 %a, i8 %neg + %m2 = select i1 %cmp2, i8 %neg, i8 %a + %r = or i8 %m2, %m1 + ret i8 %r +} + +; xor (nabs a), (nabs a) --> 0 + +define i8 @nabs_swapped(i8 %a) { +; CHECK-LABEL: @nabs_swapped( +; CHECK-NEXT: ret i8 0 +; + %neg = sub i8 0, %a + %cmp1 = icmp slt i8 %a, 0 + %cmp2 = icmp sgt i8 %a, 0 + %m1 = select i1 %cmp1, i8 %a, i8 %neg + %m2 = select i1 %cmp2, i8 %neg, i8 %a + %r = xor i8 %m2, %m1 + ret i8 %r +} + +; xor (abs a), (abs a) --> 0 + +define i8 @abs_ diff erent_constants(i8 %a) { +; CHECK-LABEL: @abs_ diff erent_constants( +; CHECK-NEXT: ret i8 0 +; + %neg = sub i8 0, %a + %cmp1 = icmp sgt i8 %a, -1 + %cmp2 = icmp slt i8 %a, 0 + %m1 = select i1 %cmp1, i8 %a, i8 %neg + %m2 = select i1 %cmp2, i8 %neg, i8 %a + %r = xor i8 %m2, %m1 + ret i8 %r +} + +; or (nabs a), (nabs a) --> nabs a + +define i8 @nabs_ diff erent_constants(i8 %a) { +; CHECK-LABEL: @nabs_ diff erent_constants( +; CHECK-NEXT: [[NEG:%.*]] = sub i8 0, [[A:%.*]] +; CHECK-NEXT: [[CMP1:%.*]] = icmp slt i8 [[A]], 0 +; CHECK-NEXT: [[M1:%.*]] = select i1 [[CMP1]], i8 [[A]], i8 [[NEG]] +; CHECK-NEXT: ret i8 [[M1]] +; + %neg = sub i8 0, %a + %cmp1 = icmp slt i8 %a, 0 + %cmp2 = icmp sgt i8 %a, -1 + %m1 = select i1 %cmp1, i8 %a, i8 %neg + %m2 = select i1 %cmp2, i8 %neg, i8 %a + %r = or i8 %m2, %m1 + ret i8 %r +} _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
