[llvm] r324462 - Revert [SCEV] Make isLoopEntryGuardedByCond a bit smarter
Serguei Katkov via llvm-commits
llvm-commits at lists.llvm.org
Wed Feb 7 01:10:08 PST 2018
Author: skatkov
Date: Wed Feb 7 01:10:08 2018
New Revision: 324462
URL: http://llvm.org/viewvc/llvm-project?rev=324462&view=rev
Log:
Revert [SCEV] Make isLoopEntryGuardedByCond a bit smarter
Revert rL324453 commit which causes buildbot failures.
Differential Revision: https://reviews.llvm.org/D42835
Modified:
llvm/trunk/include/llvm/IR/InstrTypes.h
llvm/trunk/lib/Analysis/ScalarEvolution.cpp
llvm/trunk/lib/IR/Instructions.cpp
llvm/trunk/test/Transforms/IRCE/conjunctive-checks.ll
llvm/trunk/test/Transforms/IRCE/decrementing-loop.ll
llvm/trunk/test/Transforms/IRCE/single-access-no-preloop.ll
llvm/trunk/test/Transforms/IndVarSimplify/loop-invariant-conditions.ll
Modified: llvm/trunk/include/llvm/IR/InstrTypes.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/IR/InstrTypes.h?rev=324462&r1=324461&r2=324462&view=diff
==============================================================================
--- llvm/trunk/include/llvm/IR/InstrTypes.h (original)
+++ llvm/trunk/include/llvm/IR/InstrTypes.h Wed Feb 7 01:10:08 2018
@@ -973,19 +973,6 @@ public:
/// @brief Return the predicate as if the operands were swapped.
static Predicate getSwappedPredicate(Predicate pred);
- /// For example, SGT -> SGE, SLT -> SLE, ULT -> ULE, UGT -> UGE.
- /// @brief Returns the non-strict version of strict comparisons.
- Predicate getNonStrictPredicate() const {
- return getNonStrictPredicate(getPredicate());
- }
-
- /// This is a static version that you can use without an instruction
- /// available.
- /// @returns the non-strict version of comparison provided in \p pred.
- /// If \p pred is not a strict comparison predicate, returns \p pred.
- /// @brief Returns the non-strict version of strict comparisons.
- static Predicate getNonStrictPredicate(Predicate pred);
-
/// @brief Provide more efficient getOperand methods.
DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
Modified: llvm/trunk/lib/Analysis/ScalarEvolution.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/ScalarEvolution.cpp?rev=324462&r1=324461&r2=324462&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/ScalarEvolution.cpp (original)
+++ llvm/trunk/lib/Analysis/ScalarEvolution.cpp Wed Feb 7 01:10:08 2018
@@ -9073,59 +9073,6 @@ ScalarEvolution::isLoopEntryGuardedByCon
if (isKnownPredicateViaConstantRanges(Pred, LHS, RHS))
return true;
- // If we cannot prove strict comparison (e.g. a > b), maybe we can prove
- // the facts (a >= b && a != b) separately. A typical situation is when the
- // non-strict comparison is known from ranges and non-equality is known from
- // dominating predicates. If we are proving strict comparison, we always try
- // to prove non-equality and non-strict comparison separately.
- auto NonStrictPredicate = ICmpInst::getNonStrictPredicate(Pred);
- const bool ProvingStrictComparison = (Pred != NonStrictPredicate);
- bool ProvedNonStrictComparison = false;
- bool ProvedNonEquality = false;
-
- if (ProvingStrictComparison) {
- ProvedNonStrictComparison =
- isKnownPredicateViaConstantRanges(NonStrictPredicate, LHS, RHS);
- ProvedNonEquality =
- isKnownPredicateViaConstantRanges(ICmpInst::ICMP_NE, LHS, RHS);
- assert((!ProvedNonStrictComparison || !ProvedNonEquality) &&
- "Why we were unable to prove (Pred, LHS, RHS) via constant ranges?");
- }
-
- // Try to prove (Pred, LHS, RHS) using isImpliedViaGuard.
- auto ProveViaGuard = [&](BasicBlock *Block) {
- if (isImpliedViaGuard(Block, Pred, LHS, RHS))
- return true;
- if (ProvingStrictComparison) {
- if (!ProvedNonStrictComparison)
- ProvedNonStrictComparison =
- isImpliedViaGuard(Block, NonStrictPredicate, LHS, RHS);
- if (!ProvedNonEquality)
- ProvedNonEquality =
- isImpliedViaGuard(Block, ICmpInst::ICMP_NE, LHS, RHS);
- if (ProvedNonStrictComparison && ProvedNonEquality)
- return true;
- }
- return false;
- };
-
- // Try to prove (Pred, LHS, RHS) using isImpliedCond.
- auto ProveViaCond = [&](Value *Condition, bool Inverse) {
- if (isImpliedCond(Pred, LHS, RHS, Condition, Inverse))
- return true;
- if (ProvingStrictComparison) {
- if (!ProvedNonStrictComparison)
- ProvedNonStrictComparison =
- isImpliedCond(NonStrictPredicate, LHS, RHS, Condition, Inverse);
- if (!ProvedNonEquality)
- ProvedNonEquality =
- isImpliedCond(ICmpInst::ICMP_NE, LHS, RHS, Condition, Inverse);
- if (ProvedNonStrictComparison && ProvedNonEquality)
- return true;
- }
- return false;
- };
-
// Starting at the loop predecessor, climb up the predecessor chain, as long
// as there are predecessors that can be found that have unique successors
// leading to the original header.
@@ -9134,7 +9081,7 @@ ScalarEvolution::isLoopEntryGuardedByCon
Pair.first;
Pair = getPredecessorWithUniqueSuccessorForBB(Pair.first)) {
- if (ProveViaGuard(Pair.first))
+ if (isImpliedViaGuard(Pair.first, Pred, LHS, RHS))
return true;
BranchInst *LoopEntryPredicate =
@@ -9143,8 +9090,9 @@ ScalarEvolution::isLoopEntryGuardedByCon
LoopEntryPredicate->isUnconditional())
continue;
- if (ProveViaCond(LoopEntryPredicate->getCondition(),
- LoopEntryPredicate->getSuccessor(0) != Pair.second))
+ if (isImpliedCond(Pred, LHS, RHS,
+ LoopEntryPredicate->getCondition(),
+ LoopEntryPredicate->getSuccessor(0) != Pair.second))
return true;
}
@@ -9156,7 +9104,7 @@ ScalarEvolution::isLoopEntryGuardedByCon
if (!DT.dominates(CI, L->getHeader()))
continue;
- if (ProveViaCond(CI->getArgOperand(0), false))
+ if (isImpliedCond(Pred, LHS, RHS, CI->getArgOperand(0), false))
return true;
}
Modified: llvm/trunk/lib/IR/Instructions.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/IR/Instructions.cpp?rev=324462&r1=324461&r2=324462&view=diff
==============================================================================
--- llvm/trunk/lib/IR/Instructions.cpp (original)
+++ llvm/trunk/lib/IR/Instructions.cpp Wed Feb 7 01:10:08 2018
@@ -3467,20 +3467,6 @@ CmpInst::Predicate CmpInst::getSwappedPr
}
}
-CmpInst::Predicate CmpInst::getNonStrictPredicate(Predicate pred) {
- switch (pred) {
- case ICMP_SGT: return ICMP_SGE;
- case ICMP_SLT: return ICMP_SLE;
- case ICMP_UGT: return ICMP_UGE;
- case ICMP_ULT: return ICMP_ULE;
- case FCMP_OGT: return FCMP_OGE;
- case FCMP_OLT: return FCMP_OLE;
- case FCMP_UGT: return FCMP_UGE;
- case FCMP_ULT: return FCMP_ULE;
- default: return pred;
- }
-}
-
CmpInst::Predicate CmpInst::getSignedPredicate(Predicate pred) {
assert(CmpInst::isUnsigned(pred) && "Call only with signed predicates!");
Modified: llvm/trunk/test/Transforms/IRCE/conjunctive-checks.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/IRCE/conjunctive-checks.ll?rev=324462&r1=324461&r2=324462&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/IRCE/conjunctive-checks.ll (original)
+++ llvm/trunk/test/Transforms/IRCE/conjunctive-checks.ll Wed Feb 7 01:10:08 2018
@@ -4,10 +4,10 @@ define void @f_0(i32 *%arr, i32 *%a_len_
; CHECK-LABEL: @f_0(
; CHECK: loop.preheader:
-; CHECK: [[not_safe_range_end:[^ ]+]] = sub i32 3, %len
; CHECK: [[not_n:[^ ]+]] = sub i32 -1, %n
-; CHECK: [[not_exit_main_loop_at_hiclamp_cmp:[^ ]+]] = icmp sgt i32 [[not_safe_range_end]], [[not_n]]
-; CHECK: [[not_exit_main_loop_at_hiclamp:[^ ]+]] = select i1 [[not_exit_main_loop_at_hiclamp_cmp]], i32 [[not_safe_range_end]], i32 [[not_n]]
+; CHECK: [[not_safe_range_end:[^ ]+]] = sub i32 3, %len
+; CHECK: [[not_exit_main_loop_at_hiclamp_cmp:[^ ]+]] = icmp sgt i32 [[not_n]], [[not_safe_range_end]]
+; CHECK: [[not_exit_main_loop_at_hiclamp:[^ ]+]] = select i1 [[not_exit_main_loop_at_hiclamp_cmp]], i32 [[not_n]], i32 [[not_safe_range_end]]
; CHECK: [[exit_main_loop_at_hiclamp:[^ ]+]] = sub i32 -1, [[not_exit_main_loop_at_hiclamp]]
; CHECK: [[exit_main_loop_at_loclamp_cmp:[^ ]+]] = icmp sgt i32 [[exit_main_loop_at_hiclamp]], 0
; CHECK: [[exit_main_loop_at_loclamp:[^ ]+]] = select i1 [[exit_main_loop_at_loclamp_cmp]], i32 [[exit_main_loop_at_hiclamp]], i32 0
Modified: llvm/trunk/test/Transforms/IRCE/decrementing-loop.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/IRCE/decrementing-loop.ll?rev=324462&r1=324461&r2=324462&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/IRCE/decrementing-loop.ll (original)
+++ llvm/trunk/test/Transforms/IRCE/decrementing-loop.ll Wed Feb 7 01:10:08 2018
@@ -1,8 +1,4 @@
-; RUN: opt -verify-loop-info -irce -debug-only=irce -S < %s 2>&1 | FileCheck %s
-
-; CHECK-LABEL: irce: in function decrementing_loop: constrained Loop at depth 1
-; CHECK-LABEL: irce: in function test_01: constrained Loop at depth 1
-; CHECK-LABEL: irce: in function test_02: constrained Loop at depth 1
+; RUN: opt -verify-loop-info -irce -S < %s | FileCheck %s
define void @decrementing_loop(i32 *%arr, i32 *%a_len_ptr, i32 %n) {
entry:
@@ -42,85 +38,5 @@ define void @decrementing_loop(i32 *%arr
; CHECK: %exit.preloop.at = add i32 [[not_exit_preloop_at]], -1
}
-; Make sure that we can eliminate the range check when the loop looks like:
-; for (i = len.a - 1; i >= 0; --i)
-; b[i] = a[i];
-define void @test_01(i32* %a, i32* %b, i32* %a_len_ptr, i32* %b_len_ptr) {
-
-; CHECK-LABEL: test_01
-; CHECK: mainloop:
-; CHECK-NEXT: br label %loop
-; CHECK: loop:
-; CHECK: %rc = and i1 true, true
-; CHECK: loop.preloop:
-
- entry:
- %len.a = load i32, i32* %a_len_ptr, !range !0
- %len.b = load i32, i32* %b_len_ptr, !range !0
- %first.itr.check = icmp ne i32 %len.a, 0
- br i1 %first.itr.check, label %loop, label %exit
-
- loop:
- %idx = phi i32 [ %len.a, %entry ] , [ %idx.next, %in.bounds ]
- %idx.next = sub i32 %idx, 1
- %rca = icmp ult i32 %idx.next, %len.a
- %rcb = icmp ult i32 %idx.next, %len.b
- %rc = and i1 %rca, %rcb
- br i1 %rc, label %in.bounds, label %out.of.bounds, !prof !1
-
- in.bounds:
- %el.a = getelementptr i32, i32* %a, i32 %idx.next
- %el.b = getelementptr i32, i32* %b, i32 %idx.next
- %v = load i32, i32* %el.a
- store i32 %v, i32* %el.b
- %loop.cond = icmp slt i32 %idx, 2
- br i1 %loop.cond, label %exit, label %loop
-
- out.of.bounds:
- ret void
-
- exit:
- ret void
-}
-
-; Same as test_01, but the latch condition is unsigned
-define void @test_02(i32* %a, i32* %b, i32* %a_len_ptr, i32* %b_len_ptr) {
-
-; CHECK-LABEL: test_02
-; CHECK: mainloop:
-; CHECK-NEXT: br label %loop
-; CHECK: loop:
-; CHECK: %rc = and i1 true, true
-; CHECK: loop.preloop:
-
- entry:
- %len.a = load i32, i32* %a_len_ptr, !range !0
- %len.b = load i32, i32* %b_len_ptr, !range !0
- %first.itr.check = icmp ne i32 %len.a, 0
- br i1 %first.itr.check, label %loop, label %exit
-
- loop:
- %idx = phi i32 [ %len.a, %entry ] , [ %idx.next, %in.bounds ]
- %idx.next = sub i32 %idx, 1
- %rca = icmp ult i32 %idx.next, %len.a
- %rcb = icmp ult i32 %idx.next, %len.b
- %rc = and i1 %rca, %rcb
- br i1 %rc, label %in.bounds, label %out.of.bounds, !prof !1
-
- in.bounds:
- %el.a = getelementptr i32, i32* %a, i32 %idx.next
- %el.b = getelementptr i32, i32* %b, i32 %idx.next
- %v = load i32, i32* %el.a
- store i32 %v, i32* %el.b
- %loop.cond = icmp ult i32 %idx, 2
- br i1 %loop.cond, label %exit, label %loop
-
- out.of.bounds:
- ret void
-
- exit:
- ret void
-}
-
!0 = !{i32 0, i32 2147483647}
!1 = !{!"branch_weights", i32 64, i32 4}
Modified: llvm/trunk/test/Transforms/IRCE/single-access-no-preloop.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/IRCE/single-access-no-preloop.ll?rev=324462&r1=324461&r2=324462&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/IRCE/single-access-no-preloop.ll (original)
+++ llvm/trunk/test/Transforms/IRCE/single-access-no-preloop.ll Wed Feb 7 01:10:08 2018
@@ -85,10 +85,10 @@ define void @single_access_no_preloop_wi
; CHECK-LABEL: @single_access_no_preloop_with_offset(
; CHECK: loop.preheader:
-; CHECK: [[not_safe_range_end:[^ ]+]] = sub i32 3, %len
; CHECK: [[not_n:[^ ]+]] = sub i32 -1, %n
-; CHECK: [[not_exit_main_loop_at_hiclamp_cmp:[^ ]+]] = icmp sgt i32 [[not_safe_range_end]], [[not_n]]
-; CHECK: [[not_exit_main_loop_at_hiclamp:[^ ]+]] = select i1 [[not_exit_main_loop_at_hiclamp_cmp]], i32 [[not_safe_range_end]], i32 [[not_n]]
+; CHECK: [[not_safe_range_end:[^ ]+]] = sub i32 3, %len
+; CHECK: [[not_exit_main_loop_at_hiclamp_cmp:[^ ]+]] = icmp sgt i32 [[not_n]], [[not_safe_range_end]]
+; CHECK: [[not_exit_main_loop_at_hiclamp:[^ ]+]] = select i1 [[not_exit_main_loop_at_hiclamp_cmp]], i32 [[not_n]], i32 [[not_safe_range_end]]
; CHECK: [[exit_main_loop_at_hiclamp:[^ ]+]] = sub i32 -1, [[not_exit_main_loop_at_hiclamp]]
; CHECK: [[exit_main_loop_at_loclamp_cmp:[^ ]+]] = icmp sgt i32 [[exit_main_loop_at_hiclamp]], 0
; CHECK: [[exit_main_loop_at_loclamp:[^ ]+]] = select i1 [[exit_main_loop_at_loclamp_cmp]], i32 [[exit_main_loop_at_hiclamp]], i32 0
Modified: llvm/trunk/test/Transforms/IndVarSimplify/loop-invariant-conditions.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/IndVarSimplify/loop-invariant-conditions.ll?rev=324462&r1=324461&r2=324462&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/IndVarSimplify/loop-invariant-conditions.ll (original)
+++ llvm/trunk/test/Transforms/IndVarSimplify/loop-invariant-conditions.ll Wed Feb 7 01:10:08 2018
@@ -325,36 +325,6 @@ exit:
ret void
}
-; check that we can figure out that iv.next > 1 from the facts that iv >= 0 and
-; iv.start != 0.
-define void @test11(i64* %inc_ptr) {
-; CHECK-LABEL: @test11
-entry:
- %inc = load i64, i64* %inc_ptr, !range !0
- %ne.cond = icmp ne i64 %inc, 0
- br i1 %ne.cond, label %loop, label %exit
-
-loop:
- %iv = phi i64 [ %inc, %entry ], [ %iv.next, %backedge ]
- %iv.next = add i64 %iv, 1
- %brcond = icmp sgt i64 %iv.next, 1
- ; CHECK: br i1 true, label %if.true, label %if.false
- br i1 %brcond, label %if.true, label %if.false
-
-if.true:
- br label %backedge
-
-if.false:
- br label %backedge
-
-backedge:
- %loopcond = icmp slt i64 %iv, 200
- br i1 %loopcond, label %loop, label %exit
-
-exit:
- ret void
-}
-
!1 = !{i64 -1, i64 100}
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