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LoopUnroller: Teach the loop unroller about >= terminated loops #8943

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Merged
merged 2 commits into from
Apr 23, 2017
Merged

LoopUnroller: Teach the loop unroller about >= terminated loops #8943

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533044d
LoopUnroller: Teach the loop unroller about >= terminated loops
aschwaighofer Apr 22, 2017
cafe582
LoopUnroller: Also handle > exit condition
aschwaighofer Apr 23, 2017
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19 changes: 16 additions & 3 deletions lib/SILOptimizer/LoopTransforms/LoopUnroll.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -126,10 +126,23 @@ static Optional<uint64_t> getMaxLoopTripCount(SILLoop *Loop,
IntegerLiteralInst *End;
SILValue RecNext;

unsigned Adjust = 0;

if (!match(CondBr->getCondition(),
m_BuiltinInst(BuiltinValueKind::ICMP_EQ, m_SILValue(RecNext),
m_IntegerLiteralInst(End))))
return None;
m_IntegerLiteralInst(End))) &&
!match(CondBr->getCondition(),
m_BuiltinInst(BuiltinValueKind::ICMP_SGE, m_SILValue(RecNext),
m_IntegerLiteralInst(End)))) {
if (!match(CondBr->getCondition(),
m_BuiltinInst(BuiltinValueKind::ICMP_SGT, m_SILValue(RecNext),
m_IntegerLiteralInst(End))))
return None;
// Otherwise, we have a greater than comparison.
else
Adjust = 1;
}

if (!match(RecNext,
m_TupleExtractInst(m_ApplyInst(BuiltinValueKind::SAddOver,
m_SILPHIArgument(RecArg), m_One()),
Expand Down Expand Up @@ -159,7 +172,7 @@ static Optional<uint64_t> getMaxLoopTripCount(SILLoop *Loop,
if (Dist == 0)
return None;

return Dist.getZExtValue();
return Dist.getZExtValue() + Adjust;
}

/// Check whether we can duplicate the instructions in the loop and use a
Expand Down
72 changes: 72 additions & 0 deletions test/SILOptimizer/loop_unroll.sil
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Expand Up @@ -71,6 +71,78 @@ bb3:
return %8 : $()
}

// CHECK-LABEL: sil @loop_unroll_3
// CHECK: bb0:
// CHECK: br bb1
// CHECK: bb1
// CHECK: = builtin "sadd_with_overflow_Int64
// CHECK: cond_br {{.*}}, bb3, bb2
// CHECK: bb2:
// CHECK: br bb4
// CHECK: bb3:
// CHECK: return
// CHECK: bb4
// CHECK: = builtin "sadd_with_overflow_Int64
// CHECK: br bb3

sil @loop_unroll_3 : $@convention(thin) () -> () {
bb0:
%0 = integer_literal $Builtin.Int64, 0
%1 = integer_literal $Builtin.Int64, 1
%2 = integer_literal $Builtin.Int64, 2
%3 = integer_literal $Builtin.Int1, 1
br bb1(%0 : $Builtin.Int64)

bb1(%4 : $Builtin.Int64):
%5 = builtin "sadd_with_overflow_Int64"(%4 : $Builtin.Int64, %1 : $Builtin.Int64, %3 : $Builtin.Int1) : $(Builtin.Int64, Builtin.Int1)
%6 = tuple_extract %5 : $(Builtin.Int64, Builtin.Int1), 0
%7 = builtin "cmp_sge_Int64"(%6 : $Builtin.Int64, %2 : $Builtin.Int64) : $Builtin.Int1
cond_br %7, bb3, bb2

bb2:
br bb1(%6 : $Builtin.Int64)

bb3:
%8 = tuple()
return %8 : $()
}

// CHECK-LABEL: sil @loop_unroll_4
// CHECK: bb0:
// CHECK: br bb1
// CHECK: bb1
// CHECK: = builtin "sadd_with_overflow_Int64
// CHECK: cond_br {{.*}}, bb3, bb2
// CHECK: bb2:
// CHECK: br bb4
// CHECK: bb3:
// CHECK: return
// CHECK: bb4
// CHECK: = builtin "sadd_with_overflow_Int64
// CHECK: br bb3

sil @loop_unroll_4 : $@convention(thin) () -> () {
bb0:
%0 = integer_literal $Builtin.Int64, 0
%1 = integer_literal $Builtin.Int64, 1
%2 = integer_literal $Builtin.Int64, 1
%3 = integer_literal $Builtin.Int1, 1
br bb1(%0 : $Builtin.Int64)

bb1(%4 : $Builtin.Int64):
%5 = builtin "sadd_with_overflow_Int64"(%4 : $Builtin.Int64, %1 : $Builtin.Int64, %3 : $Builtin.Int1) : $(Builtin.Int64, Builtin.Int1)
%6 = tuple_extract %5 : $(Builtin.Int64, Builtin.Int1), 0
%7 = builtin "cmp_sgt_Int64"(%6 : $Builtin.Int64, %2 : $Builtin.Int64) : $Builtin.Int1
cond_br %7, bb3, bb2

bb2:
br bb1(%6 : $Builtin.Int64)

bb3:
%8 = tuple()
return %8 : $()
}

class B {}

// CHECK-LABEL: sil @unroll_with_stack_allocation
Expand Down