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llvm-project/llvm/test/Transforms/IndVarSimplify/pr39673.ll

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Revert "Temporarily Revert "Add basic loop fusion pass."" The reversion apparently deleted the test/Transforms directory. Will be re-reverting again. llvm-svn: 358552
2019-04-17 12:52:47 +08:00
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
[LoopPred] Selectively disable to preserve test cases I'm about to enable the new loop predication transform by default. It has the effect of completely destroying many read only loops - which happen to be a super common idiom in our test cases. So as to preserve test coverage of other transforms, disable the new transform where it would cause sharp test coverage regressions. (This is semantically part of the enabling commit. It's committed separate to ease revert if the actual flag flip gets reverted.)
2019-11-07 07:16:43 +08:00
; RUN: opt -S -indvars -indvars-predicate-loops=0 < %s | FileCheck %s
Revert "Temporarily Revert "Add basic loop fusion pass."" The reversion apparently deleted the test/Transforms directory. Will be re-reverting again. llvm-svn: 358552
2019-04-17 12:52:47 +08:00
[Tests] Add tests to highlight sibling loop optimization order issue for exit rewriting The issue addressed in r363180 is more broadly relevant. For the moment, we don't actually get any of these cases because we a) restrict SCEV formation due to SCEExpander needing to preserve LCSSA, and b) don't iterate between loops. llvm-svn: 363192
2019-06-13 03:04:51 +08:00
define i16 @constant() {
; CHECK-LABEL: @constant(
Revert "Temporarily Revert "Add basic loop fusion pass."" The reversion apparently deleted the test/Transforms directory. Will be re-reverting again. llvm-svn: 358552
2019-04-17 12:52:47 +08:00
; CHECK-NEXT: entry:
; CHECK-NEXT: br label [[LOOP1:%.*]]
; CHECK: loop1:
; CHECK-NEXT: [[L1:%.*]] = phi i16 [ 0, [[ENTRY:%.*]] ], [ [[L1_ADD:%.*]], [[LOOP1]] ]
; CHECK-NEXT: [[L1_ADD]] = add nuw nsw i16 [[L1]], 1
; CHECK-NEXT: [[CMP1:%.*]] = icmp ult i16 [[L1_ADD]], 2
; CHECK-NEXT: br i1 [[CMP1]], label [[LOOP1]], label [[LOOP2_PREHEADER:%.*]]
; CHECK: loop2.preheader:
; CHECK-NEXT: br label [[LOOP2:%.*]]
; CHECK: loop2:
; CHECK-NEXT: [[K2:%.*]] = phi i16 [ [[K2_ADD:%.*]], [[LOOP2]] ], [ 182, [[LOOP2_PREHEADER]] ]
; CHECK-NEXT: [[L2:%.*]] = phi i16 [ [[L2_ADD:%.*]], [[LOOP2]] ], [ 0, [[LOOP2_PREHEADER]] ]
; CHECK-NEXT: [[L2_ADD]] = add nuw nsw i16 [[L2]], 1
; CHECK-NEXT: tail call void @foo(i16 [[K2]])
; CHECK-NEXT: [[K2_ADD]] = add nuw nsw i16 [[K2]], 1
; CHECK-NEXT: [[CMP2:%.*]] = icmp ult i16 [[L2_ADD]], 2
; CHECK-NEXT: br i1 [[CMP2]], label [[LOOP2]], label [[LOOP2_END:%.*]]
; CHECK: loop2.end:
[SCEV] Teach computeSCEVAtScope benefit from one-input Phi. PR39673 SCEV does not propagate arguments through one-input Phis so as to make it easy for the SCEV expander (and related code) to preserve LCSSA. It's not entirely clear this restriction is neccessary, but for the moment it exists. For this reason, we don't analyze single-entry phi inputs. However it is possible that when an this input leaves the loop through LCSSA Phi, it is a provable constant. Missing that results in an order of optimization issue in loop exit value rewriting where we miss some oppurtunities based on order in which we visit sibling loops. This patch teaches computeSCEVAtScope about this case. We can generalize it later, but so far we can only replace LCSSA Phis with their constant loop-exiting values. We should probably also add similiar logic directly in the SCEV construction path itself. Patch by: mkazantsev (with revised commit message by me) Differential Revision: https://reviews.llvm.org/D58113 llvm-svn: 363180
2019-06-13 01:21:47 +08:00
; CHECK-NEXT: ret i16 184
Revert "Temporarily Revert "Add basic loop fusion pass."" The reversion apparently deleted the test/Transforms directory. Will be re-reverting again. llvm-svn: 358552
2019-04-17 12:52:47 +08:00
;
entry:
br label %loop1
loop1: ; preds = %entry, %loop1
%k1 = phi i16 [ 180, %entry ], [ %k1.add, %loop1 ]
%l1 = phi i16 [ 0, %entry ], [ %l1.add, %loop1 ]
%k1.add = add nuw nsw i16 %k1, 1
%l1.add = add nuw nsw i16 %l1, 1
%cmp1 = icmp ult i16 %l1.add, 2
br i1 %cmp1, label %loop1, label %loop2.preheader
loop2.preheader: ; preds = %loop1
%k1.add.lcssa = phi i16 [ %k1.add, %loop1 ]
br label %loop2
loop2: ; preds = %loop2.preheader, %loop2
%k2 = phi i16 [ %k2.add, %loop2 ], [ %k1.add.lcssa, %loop2.preheader ]
%l2 = phi i16 [ %l2.add, %loop2 ], [ 0, %loop2.preheader ]
%l2.add = add nuw i16 %l2, 1
tail call void @foo(i16 %k2)
%k2.add = add nuw nsw i16 %k2, 1
%cmp2 = icmp ult i16 %l2.add, 2
br i1 %cmp2, label %loop2, label %loop2.end
loop2.end: ; preds = %loop2
%k2.add.lcssa = phi i16 [ %k2.add, %loop2 ]
ret i16 %k2.add.lcssa
}
[Tests] Add tests to highlight sibling loop optimization order issue for exit rewriting The issue addressed in r363180 is more broadly relevant. For the moment, we don't actually get any of these cases because we a) restrict SCEV formation due to SCEExpander needing to preserve LCSSA, and b) don't iterate between loops. llvm-svn: 363192
2019-06-13 03:04:51 +08:00
define i16 @dom_argument(i16 %arg1, i16 %arg2) {
; CHECK-LABEL: @dom_argument(
; CHECK-NEXT: entry:
; CHECK-NEXT: br label [[LOOP1:%.*]]
; CHECK: loop1:
; CHECK-NEXT: [[L1:%.*]] = phi i16 [ 0, [[ENTRY:%.*]] ], [ [[L1_ADD:%.*]], [[LOOP1]] ]
; CHECK-NEXT: [[L1_ADD]] = add nuw nsw i16 [[L1]], 1
; CHECK-NEXT: [[CMP1:%.*]] = icmp ult i16 [[L1_ADD]], 2
; CHECK-NEXT: br i1 [[CMP1]], label [[LOOP1]], label [[LOOP2_PREHEADER:%.*]]
; CHECK: loop2.preheader:
; CHECK-NEXT: br label [[LOOP2:%.*]]
; CHECK: loop2:
Teach getSCEVAtScope how to handle loop phis w/invariant operands in loops w/taken backedges This patch really contains two pieces: Teach SCEV how to fold a phi in the header of a loop to the value on the backedge when a) the backedge is known to execute at least once, and b) the value is safe to use globally within the scope dominated by the original phi. Teach IndVarSimplify's rewriteLoopExitValues to allow loop invariant expressions which already exist (and thus don't need new computation inserted) even in loops where we can't optimize away other uses. Differential Revision: https://reviews.llvm.org/D63224 llvm-svn: 363619
2019-06-18 05:06:17 +08:00
; CHECK-NEXT: [[K2:%.*]] = phi i16 [ [[K2_ADD:%.*]], [[LOOP2]] ], [ [[ARG2:%.*]], [[LOOP2_PREHEADER]] ]
[Tests] Add tests to highlight sibling loop optimization order issue for exit rewriting The issue addressed in r363180 is more broadly relevant. For the moment, we don't actually get any of these cases because we a) restrict SCEV formation due to SCEExpander needing to preserve LCSSA, and b) don't iterate between loops. llvm-svn: 363192
2019-06-13 03:04:51 +08:00
; CHECK-NEXT: [[L2:%.*]] = phi i16 [ [[L2_ADD:%.*]], [[LOOP2]] ], [ 0, [[LOOP2_PREHEADER]] ]
; CHECK-NEXT: [[L2_ADD]] = add nuw nsw i16 [[L2]], 1
; CHECK-NEXT: tail call void @foo(i16 [[K2]])
; CHECK-NEXT: [[K2_ADD]] = add nuw nsw i16 [[K2]], 1
; CHECK-NEXT: [[CMP2:%.*]] = icmp ult i16 [[L2_ADD]], 2
; CHECK-NEXT: br i1 [[CMP2]], label [[LOOP2]], label [[LOOP2_END:%.*]]
; CHECK: loop2.end:
Revert "[SCEV] rewriteLoopExitValues(): even if have hard uses, still rewrite if cheap (PR44668)" As discussed in post-commit review in https://reviews.llvm.org/D73501 if the goal of this is to help vectorizer, then we should actually be teaching vectorizer to do this, because right now this rewrite is still budget-limited, which isn't what we'd want. Additionally, while the rest of the patch series was universally profitable, this particular patch is reportedly (https://reviews.llvm.org/D73501#1905171) exposing cost-modeling issues on ARM. So let's just back this particular patch out. Once there's an undo transform, this could be considered for reintegration. This reverts commit 44edc6fd2c63b7db43e13cc8caf1fee79bebdb5f.
2020-04-04 00:59:47 +08:00
; CHECK-NEXT: [[K2_ADD_LCSSA:%.*]] = phi i16 [ [[K2_ADD]], [[LOOP2]] ]
; CHECK-NEXT: ret i16 [[K2_ADD_LCSSA]]
[Tests] Add tests to highlight sibling loop optimization order issue for exit rewriting The issue addressed in r363180 is more broadly relevant. For the moment, we don't actually get any of these cases because we a) restrict SCEV formation due to SCEExpander needing to preserve LCSSA, and b) don't iterate between loops. llvm-svn: 363192
2019-06-13 03:04:51 +08:00
;
entry:
br label %loop1
loop1: ; preds = %entry, %loop1
%k1 = phi i16 [ 100, %entry ], [ %k1.add, %loop1 ]
%l1 = phi i16 [ 0, %entry ], [ %l1.add, %loop1 ]
%selector = phi i16 [ %arg1, %entry ], [ %arg2, %loop1 ]
%k1.add = add nuw nsw i16 %k1, 1
%l1.add = add nuw nsw i16 %l1, 1
%cmp1 = icmp ult i16 %l1.add, 2
br i1 %cmp1, label %loop1, label %loop2.preheader
loop2.preheader: ; preds = %loop1
%k1.add.lcssa = phi i16 [ %selector, %loop1 ]
br label %loop2
loop2: ; preds = %loop2.preheader, %loop2
%k2 = phi i16 [ %k2.add, %loop2 ], [ %k1.add.lcssa, %loop2.preheader ]
%l2 = phi i16 [ %l2.add, %loop2 ], [ 0, %loop2.preheader ]
%l2.add = add nuw i16 %l2, 1
tail call void @foo(i16 %k2)
%k2.add = add nuw nsw i16 %k2, 1
%cmp2 = icmp ult i16 %l2.add, 2
br i1 %cmp2, label %loop2, label %loop2.end
loop2.end: ; preds = %loop2
%k2.add.lcssa = phi i16 [ %k2.add, %loop2 ]
ret i16 %k2.add.lcssa
}
define i16 @dummy_phi_outside_loop(i16 %arg) {
; CHECK-LABEL: @dummy_phi_outside_loop(
; CHECK-NEXT: entry:
; CHECK-NEXT: br label [[LOOP2_PREHEADER:%.*]]
; CHECK: loop2.preheader:
; CHECK-NEXT: [[DUMMY:%.*]] = phi i16 [ [[ARG:%.*]], [[ENTRY:%.*]] ]
; CHECK-NEXT: br label [[LOOP2:%.*]]
; CHECK: loop2:
; CHECK-NEXT: [[K2:%.*]] = phi i16 [ [[K2_ADD:%.*]], [[LOOP2]] ], [ [[DUMMY]], [[LOOP2_PREHEADER]] ]
; CHECK-NEXT: [[L2:%.*]] = phi i16 [ [[L2_ADD:%.*]], [[LOOP2]] ], [ 0, [[LOOP2_PREHEADER]] ]
; CHECK-NEXT: [[L2_ADD]] = add nuw nsw i16 [[L2]], 1
; CHECK-NEXT: tail call void @foo(i16 [[K2]])
; CHECK-NEXT: [[K2_ADD]] = add nuw nsw i16 [[K2]], 1
; CHECK-NEXT: [[CMP2:%.*]] = icmp ult i16 [[L2_ADD]], 2
; CHECK-NEXT: br i1 [[CMP2]], label [[LOOP2]], label [[LOOP2_END:%.*]]
; CHECK: loop2.end:
Revert "[SCEV] rewriteLoopExitValues(): even if have hard uses, still rewrite if cheap (PR44668)" As discussed in post-commit review in https://reviews.llvm.org/D73501 if the goal of this is to help vectorizer, then we should actually be teaching vectorizer to do this, because right now this rewrite is still budget-limited, which isn't what we'd want. Additionally, while the rest of the patch series was universally profitable, this particular patch is reportedly (https://reviews.llvm.org/D73501#1905171) exposing cost-modeling issues on ARM. So let's just back this particular patch out. Once there's an undo transform, this could be considered for reintegration. This reverts commit 44edc6fd2c63b7db43e13cc8caf1fee79bebdb5f.
2020-04-04 00:59:47 +08:00
; CHECK-NEXT: [[K2_ADD_LCSSA:%.*]] = phi i16 [ [[K2_ADD]], [[LOOP2]] ]
; CHECK-NEXT: ret i16 [[K2_ADD_LCSSA]]
[Tests] Add tests to highlight sibling loop optimization order issue for exit rewriting The issue addressed in r363180 is more broadly relevant. For the moment, we don't actually get any of these cases because we a) restrict SCEV formation due to SCEExpander needing to preserve LCSSA, and b) don't iterate between loops. llvm-svn: 363192
2019-06-13 03:04:51 +08:00
;
entry:
br label %loop2.preheader
loop2.preheader: ; preds = %loop1
%dummy = phi i16 [ %arg, %entry ]
br label %loop2
loop2: ; preds = %loop2.preheader, %loop2
%k2 = phi i16 [ %k2.add, %loop2 ], [ %dummy, %loop2.preheader ]
%l2 = phi i16 [ %l2.add, %loop2 ], [ 0, %loop2.preheader ]
%l2.add = add nuw i16 %l2, 1
tail call void @foo(i16 %k2)
%k2.add = add nuw nsw i16 %k2, 1
%cmp2 = icmp ult i16 %l2.add, 2
br i1 %cmp2, label %loop2, label %loop2.end
loop2.end: ; preds = %loop2
%k2.add.lcssa = phi i16 [ %k2.add, %loop2 ]
ret i16 %k2.add.lcssa
}
define i16 @neg_loop_carried(i16 %arg) {
; CHECK-LABEL: @neg_loop_carried(
; CHECK-NEXT: entry:
; CHECK-NEXT: br label [[LOOP1:%.*]]
; CHECK: loop1:
; CHECK-NEXT: [[L1:%.*]] = phi i16 [ 0, [[ENTRY:%.*]] ], [ [[L1_ADD:%.*]], [[LOOP1]] ]
; CHECK-NEXT: [[L1_ADD]] = add nuw nsw i16 [[L1]], 1
; CHECK-NEXT: [[CMP1:%.*]] = icmp ult i16 [[L1_ADD]], 2
; CHECK-NEXT: br i1 [[CMP1]], label [[LOOP1]], label [[LOOP2_PREHEADER:%.*]]
; CHECK: loop2.preheader:
; CHECK-NEXT: [[TMP0:%.*]] = add i16 [[ARG:%.*]], 2
; CHECK-NEXT: br label [[LOOP2:%.*]]
; CHECK: loop2:
; CHECK-NEXT: [[K2:%.*]] = phi i16 [ [[K2_ADD:%.*]], [[LOOP2]] ], [ [[TMP0]], [[LOOP2_PREHEADER]] ]
; CHECK-NEXT: [[L2:%.*]] = phi i16 [ [[L2_ADD:%.*]], [[LOOP2]] ], [ 0, [[LOOP2_PREHEADER]] ]
; CHECK-NEXT: [[L2_ADD]] = add nuw nsw i16 [[L2]], 1
; CHECK-NEXT: tail call void @foo(i16 [[K2]])
; CHECK-NEXT: [[K2_ADD]] = add nuw nsw i16 [[K2]], 1
; CHECK-NEXT: [[CMP2:%.*]] = icmp ult i16 [[L2_ADD]], 2
; CHECK-NEXT: br i1 [[CMP2]], label [[LOOP2]], label [[LOOP2_END:%.*]]
; CHECK: loop2.end:
Revert "[SCEV] rewriteLoopExitValues(): even if have hard uses, still rewrite if cheap (PR44668)" As discussed in post-commit review in https://reviews.llvm.org/D73501 if the goal of this is to help vectorizer, then we should actually be teaching vectorizer to do this, because right now this rewrite is still budget-limited, which isn't what we'd want. Additionally, while the rest of the patch series was universally profitable, this particular patch is reportedly (https://reviews.llvm.org/D73501#1905171) exposing cost-modeling issues on ARM. So let's just back this particular patch out. Once there's an undo transform, this could be considered for reintegration. This reverts commit 44edc6fd2c63b7db43e13cc8caf1fee79bebdb5f.
2020-04-04 00:59:47 +08:00
; CHECK-NEXT: [[K2_ADD_LCSSA:%.*]] = phi i16 [ [[K2_ADD]], [[LOOP2]] ]
; CHECK-NEXT: ret i16 [[K2_ADD_LCSSA]]
[Tests] Add tests to highlight sibling loop optimization order issue for exit rewriting The issue addressed in r363180 is more broadly relevant. For the moment, we don't actually get any of these cases because we a) restrict SCEV formation due to SCEExpander needing to preserve LCSSA, and b) don't iterate between loops. llvm-svn: 363192
2019-06-13 03:04:51 +08:00
;
entry:
br label %loop1
loop1: ; preds = %entry, %loop1
%k1 = phi i16 [ %arg, %entry ], [ %k1.add, %loop1 ]
%l1 = phi i16 [ 0, %entry ], [ %l1.add, %loop1 ]
%k1.add = add nuw nsw i16 %k1, 1
%l1.add = add nuw nsw i16 %l1, 1
%cmp1 = icmp ult i16 %l1.add, 2
br i1 %cmp1, label %loop1, label %loop2.preheader
loop2.preheader: ; preds = %loop1
%k1.add.lcssa = phi i16 [ %k1.add, %loop1 ]
br label %loop2
loop2: ; preds = %loop2.preheader, %loop2
%k2 = phi i16 [ %k2.add, %loop2 ], [ %k1.add.lcssa, %loop2.preheader ]
%l2 = phi i16 [ %l2.add, %loop2 ], [ 0, %loop2.preheader ]
%l2.add = add nuw i16 %l2, 1
tail call void @foo(i16 %k2)
%k2.add = add nuw nsw i16 %k2, 1
%cmp2 = icmp ult i16 %l2.add, 2
br i1 %cmp2, label %loop2, label %loop2.end
loop2.end: ; preds = %loop2
%k2.add.lcssa = phi i16 [ %k2.add, %loop2 ]
ret i16 %k2.add.lcssa
}
Revert "Temporarily Revert "Add basic loop fusion pass."" The reversion apparently deleted the test/Transforms directory. Will be re-reverting again. llvm-svn: 358552
2019-04-17 12:52:47 +08:00
declare void @foo(i16)