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Enable loop rotate when the header is exiting #79198

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15 changes: 5 additions & 10 deletions lib/SILOptimizer/LoopTransforms/LoopRotate.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -44,6 +44,9 @@ static llvm::cl::opt<int> LoopRotateSizeLimit("looprotate-size-limit",
llvm::cl::init(20));
static llvm::cl::opt<bool> RotateSingleBlockLoop("looprotate-single-block-loop",
llvm::cl::init(false));
static llvm::cl::opt<bool>
LoopRotateInfiniteBudget("looprotate-infinite-budget",
llvm::cl::init(false));

static bool rotateLoop(SILLoop *loop, DominanceInfo *domInfo,
SILLoopInfo *loopInfo, bool rotateSingleBlockLoops,
Expand Down Expand Up @@ -118,9 +121,7 @@ canDuplicateOrMoveToPreheader(SILLoop *loop, SILBasicBlock *preheader,
if (!inst->mayHaveSideEffects() && !inst->mayReadFromMemory() &&
!isa<TermInst>(inst) &&
!isa<AllocationInst>(inst) && /* not marked mayhavesideeffects */
!isa<CopyValueInst>(inst) &&
!isa<MoveValueInst>(inst) &&
!isa<BeginBorrowInst>(inst) &&
!hasOwnershipOperandsOrResults(inst) &&
hasLoopInvariantOperands(inst, loop, invariants)) {
moves.push_back(inst);
invariants.insert(inst);
Expand All @@ -133,7 +134,7 @@ canDuplicateOrMoveToPreheader(SILLoop *loop, SILBasicBlock *preheader,
cost += (int)instructionInlineCost(instRef);
}

return cost < LoopRotateSizeLimit;
return cost < LoopRotateSizeLimit || LoopRotateInfiniteBudget;
}

static void mapOperands(SILInstruction *inst,
Expand Down Expand Up @@ -369,12 +370,6 @@ static bool rotateLoop(SILLoop *loop, DominanceInfo *domInfo,
assert(loop->contains(newHeader) && !loop->contains(exit)
&& "Could not find loop header and exit block");

// It does not make sense to rotate the loop if the new header is loop
// exiting as well.
if (loop->isLoopExiting(newHeader)) {
return false;
}

// Incomplete liveranges in the dead-end exit block can cause a missing adjacent
// phi-argument for a re-borrow if there is a borrow-scope is in the loop.
// But even when we have complete lifetimes, it's probably not worth rotating
Expand Down
39 changes: 37 additions & 2 deletions test/SILOptimizer/looprotate_nontrivial_ossa.sil
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Original file line number Diff line number Diff line change
@@ -1,11 +1,10 @@
// RUN: %target-sil-opt -loop-rotate -update-borrowed-from -looprotate-single-block-loop=true %s | %FileCheck %s
// RUN: %target-sil-opt -loop-rotate -update-borrowed-from -looprotate-single-block-loop=true -looprotate-infinite-budget %s | %FileCheck %s
sil_stage canonical

import Builtin
import Swift

class Klass {

}

struct BoxStruct {
Expand Down Expand Up @@ -244,3 +243,39 @@ bb8:
bb9:
unreachable
}

sil @foo : $@convention(thin) (@in_guaranteed UInt64, @in_guaranteed UInt64) -> (Bool, @error any Error)

sil [ossa] @looprotate_ownership_results : $@convention(thin) (Int32, @guaranteed Klass) -> Int32 {
bb0(%0 : $Int32, %1 : @guaranteed $Klass):
%2 = struct_extract %0, #Int32._value
%3 = integer_literal $Builtin.Int32, 0
br bb1(%2, %3)

bb1(%5 : $Builtin.Int32, %6 : $Builtin.Int32):
%7 = function_ref @foo : $@convention(thin) (@in_guaranteed UInt64, @in_guaranteed UInt64) -> (Bool, @error any Error)
%8 = thin_to_thick_function %7 to $@noescape @callee_guaranteed (@in_guaranteed UInt64, @in_guaranteed UInt64) -> (Bool, @error any Error)
%9 = convert_function %8 to $@noescape @callee_guaranteed @substituted <τ_0_0, τ_0_1> (@in_guaranteed τ_0_0, @in_guaranteed τ_0_1) -> (Bool, @error any Error) for <UInt64, UInt64>, forwarding: @owned
destroy_value %9
%11 = struct $Int32 (%6)
%12 = builtin "cmp_eq_Word"(%6, %2) : $Builtin.Int1
cond_br %12, bb3, bb2

bb2:
%14 = integer_literal $Builtin.Int32, 1
%15 = integer_literal $Builtin.Int1, -1
%16 = builtin "sadd_with_overflow_Word"(%6, %14, %15) : $(Builtin.Int32, Builtin.Int1)
%17 = tuple_extract %16, 0
%18 = enum $Optional<Int32>, #Optional.some!enumelt, %11
%19 = unchecked_enum_data %18, #Optional.some!enumelt
%20 = struct_extract %19, #Int32._value
%21 = integer_literal $Builtin.Int1, -1
%22 = builtin "sadd_with_overflow_Word"(%5, %20, %21) : $(Builtin.Int32, Builtin.Int1)
%23 = tuple_extract %22, 0
br bb1(%23, %17)

bb3:
%25 = struct $Int32 (%5)
return %25
}

17 changes: 7 additions & 10 deletions test/SILOptimizer/looprotate_ossa.sil
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Original file line number Diff line number Diff line change
Expand Up @@ -85,16 +85,13 @@ bb3:
return %23 : $Int32
}

// CHECK-LABEL: sil [ossa] @dont_rotate_multi_exit_loop :
// CHECK: bb1({{.*}}):
// CHECK: cond_br %{{.*}}, bb4, bb2
// CHECK: bb2:
// CHECK: cond_br undef, bb3, bb5
// CHECK: bb6:
// CHECK: return
// CHECK-NOT: bb7
// CHECK: } // end sil function 'dont_rotate_multi_exit_loop'
sil [ossa] @dont_rotate_multi_exit_loop : $@convention(thin) (Int32, @owned Bar) -> Int32 {
// CHECK-LABEL: sil [ossa] @rotate_multi_exit_loop :
// CHECK: [[METH1:%.*]] = class_method {{.*}} : $Bar, #Bar.foo : (Bar) -> () -> (), $@convention(method) (@guaranteed Bar) -> ()
// CHECK: apply [[METH1]]({{.*}}) : $@convention(method) (@guaranteed Bar) -> ()
// CHECK: [[METH2:%.*]] = class_method {{.*}} : $Bar, #Bar.foo : (Bar) -> () -> (), $@convention(method) (@guaranteed Bar) -> ()
// CHECK: apply [[METH2]]({{.*}}) : $@convention(method) (@guaranteed Bar) -> ()
// CHECK: } // end sil function 'rotate_multi_exit_loop'
sil [ossa] @rotate_multi_exit_loop : $@convention(thin) (Int32, @owned Bar) -> Int32 {
bb0(%0 : $Int32, %25: @owned $Bar):
%1 = struct_extract %0 : $Int32, #Int32._value
%2 = integer_literal $Builtin.Int32, 0
Expand Down
2 changes: 1 addition & 1 deletion test/SILOptimizer/mutable_span_bounds_check_tests.swift
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Expand Up @@ -130,7 +130,7 @@ public func span_bubble_sort(_ span: inout MutableSpan<Int>) {
}

// CHECK-SIL-LABEL: sil @$s31mutable_span_bounds_check_tests6sortedySb10SpanExtras07MutableG0VySiGF :
// CHECK-SIL: bb4:
// CHECK-SIL: bb4({{.*}}):
// CHECK-SIL: cond_fail {{.*}}, "precondition failure"
// CHECK-SIL: cond_fail {{.*}}, "precondition failure"
// CHECK-SIL: cond_br
Expand Down
4 changes: 2 additions & 2 deletions test/SILOptimizer/span_bounds_check_tests.swift
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Expand Up @@ -244,7 +244,7 @@ public func span_element_sum(_ v: Span<Int>, _ i: Int) -> Int {
// CHECK-SIL-LABEL: sil @$s23span_bounds_check_tests0A7_searchySiSgs4SpanVyxG_xtSQRzlF :
// CHECK-SIL: bb3:
// CHECK-SIL: cond_fail {{.*}}, "Index out of bounds"
// CHECK-SIL: cond_fail {{.*}}, "Index out of bounds"
// CHECK-SIL-NOT: cond_fail {{.*}}, "Index out of bounds"
// CHECK-SIL: cond_br
// CHECK-SIL-LABEL: } // end sil function '$s23span_bounds_check_tests0A7_searchySiSgs4SpanVyxG_xtSQRzlF'
public func span_search<T : Equatable>(_ v: Span<T>, _ elem: T) -> Int? {
Expand All @@ -261,7 +261,7 @@ public func span_search<T : Equatable>(_ v: Span<T>, _ elem: T) -> Int? {
// CHECK-SIL-LABEL: sil @$s23span_bounds_check_tests0A11_search_splySiSgs4SpanVySiG_SitF :
// CHECK-SIL: bb3:
// CHECK-SIL: cond_fail {{.*}}, "Index out of bounds"
// CHECK-SIL: cond_fail {{.*}}, "Index out of bounds"
// CHECK-SIL-NOT: cond_fail {{.*}}, "Index out of bounds"
// CHECK-SIL: cond_br
// CHECK-SIL-LABEL: } // end sil function '$s23span_bounds_check_tests0A11_search_splySiSgs4SpanVySiG_SitF'
public func span_search_spl(_ v: Span<Int>, _ elem: Int) -> Int? {
Expand Down