diff options
author | 2021-05-19 17:29:00 +0100 | |
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committer | 2021-10-21 12:37:09 +0000 | |
commit | c498a1de3de1b36baebfd7b69b0af7fb4947d58e (patch) | |
tree | 9f34ab6d331ac438b43c2f4c1a01965a4ba11877 | |
parent | 0a12631fd5364d5908d59ea476bea075019ebecd (diff) |
ART: Redundant AND operation removal optimization
In the following code:
b[i + length] = (byte) ((value & 0xff00) >> 8);
The AND operation is redundant because the lowest 8 bits will be
removed by the 8 bits right shift.
This optimization covers cases where a subsequent SHR and
Type Conversion (from Int and Short --> Byte make an AND redundant.
In such cases, the AND operation is removed. Patch also includes tests.
This patch covers only signed types.
Unsigned types will be supported in a future patch.
This optimization brings 3.3% perf increase on FFTBench workload.
Test: ./scripts/tests/test_art_target.sh --single-test\
458-checker-instruct-simplification
Can also use test_art_host.sh with same option as above.
Author: Aditya Deshpande.
Committer: Artem Serov.
Change-Id: I50b87576a3f998100feefc0e5df65b7b343d87e6
-rw-r--r-- | compiler/optimizing/instruction_simplifier.cc | 59 | ||||
-rw-r--r-- | test/458-checker-instruct-simplification/src/Main.java | 255 |
2 files changed, 313 insertions, 1 deletions
diff --git a/compiler/optimizing/instruction_simplifier.cc b/compiler/optimizing/instruction_simplifier.cc index a75639f3c5..6ff71f2d3e 100644 --- a/compiler/optimizing/instruction_simplifier.cc +++ b/compiler/optimizing/instruction_simplifier.cc @@ -24,6 +24,7 @@ #include "intrinsics.h" #include "intrinsics_utils.h" #include "mirror/class-inl.h" +#include "optimizing/data_type.h" #include "optimizing/nodes.h" #include "scoped_thread_state_change-inl.h" #include "sharpening.h" @@ -112,7 +113,6 @@ class InstructionSimplifierVisitor : public HGraphDelegateVisitor { void VisitDeoptimize(HDeoptimize* deoptimize) override; void VisitVecMul(HVecMul* instruction) override; void VisitPredicatedInstanceFieldGet(HPredicatedInstanceFieldGet* instruction) override; - void SimplifySystemArrayCopy(HInvoke* invoke); void SimplifyStringEquals(HInvoke* invoke); void SimplifyFP2Int(HInvoke* invoke); @@ -1185,6 +1185,33 @@ static bool IsTypeConversionLossless(DataType::Type input_type, DataType::Type r !(result_type == DataType::Type::kInt64 && input_type == DataType::Type::kFloat32); } +static bool CanRemoveRedundantAnd(HConstant* and_right, + HConstant* shr_right, + DataType::Type result_type) { + int64_t and_cst = Int64FromConstant(and_right); + int64_t shr_cst = Int64FromConstant(shr_right); + + // In the following sequence A is the input value, D is the result: + // B := A & x + // C := B >> r + // D := TypeConv(n-bit type) C + + // The value of D is entirely dependent on the bits [n-1:0] of C, which in turn are dependent + // on bits [r+n-1:r] of B. + // Therefore, if the AND does not change bits [r+n-1:r] of A then it will not affect D. + // This can be checked by ensuring that bits [r+n-1:r] of the AND Constant are 1. + + // For example: return (byte) ((value & 0xff00) >> 8) + // return (byte) ((value & 0xff000000) >> 31) + + // The mask sets bits [r+n-1:r] to 1, and all others to 0. + int64_t mask = DataType::MaxValueOfIntegralType(DataType::ToUnsigned(result_type)) << shr_cst; + + // If the result of a bitwise AND between the mask and the AND constant is the original mask, then + // the AND does not change bits [r+n-1:r], meaning that it is redundant and can be removed. + return ((and_cst & mask) == mask); +} + static inline bool TryReplaceFieldOrArrayGetType(HInstruction* maybe_get, DataType::Type new_type) { if (maybe_get->IsInstanceFieldGet()) { maybe_get->AsInstanceFieldGet()->SetType(new_type); @@ -1305,6 +1332,36 @@ void InstructionSimplifierVisitor::VisitTypeConversion(HTypeConversion* instruct return; } } + } else if (input->IsShr() && DataType::IsIntegralType(result_type) && + // Optimization only applies to lossy Type Conversions. + !IsTypeConversionLossless(input_type, result_type)) { + DCHECK(DataType::IsIntegralType(input_type)); + HShr* shr_op = input->AsShr(); + HConstant* shr_right = shr_op->GetConstantRight(); + HInstruction* shr_left = shr_op->GetLeastConstantLeft(); + if (shr_right != nullptr && shr_left->IsAnd()) { + // Optimization needs AND -> SHR -> TypeConversion pattern. + HAnd* and_op = shr_left->AsAnd(); + HConstant* and_right = and_op->GetConstantRight(); + HInstruction* and_left = and_op->GetLeastConstantLeft(); + DataType::Type and_left_type = and_left->GetType(); + if (!DataType::IsUnsignedType(and_left_type) && + !DataType::IsUnsignedType(result_type) && + !DataType::IsUnsignedType(and_right->GetType()) && + (DataType::Size(and_left_type) < 8) && + (DataType::Size(result_type) == 1)) { + // TODO: Support Unsigned Types. + // TODO: Support Long Types. + // TODO: Support result types other than byte. + if (and_right != nullptr && and_op->HasOnlyOneNonEnvironmentUse() && + CanRemoveRedundantAnd(and_right, shr_right, result_type)) { + and_op->ReplaceWith(and_left); + and_op->GetBlock()->RemoveInstruction(and_op); + RecordSimplification(); + return; + } + } + } } else if (input->IsAnd() && DataType::IsIntegralType(result_type)) { DCHECK(DataType::IsIntegralType(input_type)); HAnd* input_and = input->AsAnd(); diff --git a/test/458-checker-instruct-simplification/src/Main.java b/test/458-checker-instruct-simplification/src/Main.java index 5ffb75feb9..557f126d01 100644 --- a/test/458-checker-instruct-simplification/src/Main.java +++ b/test/458-checker-instruct-simplification/src/Main.java @@ -2529,6 +2529,219 @@ public class Main { return "x".indexOf(ch, fromIndex); // Not simplified. } + /// CHECK-START: byte Main.$noinline$redundantAndNotRedundant(int) instruction_simplifier (before) + /// CHECK-DAG: And + + /// CHECK-START: byte Main.$noinline$redundantAndNotRedundant(int) instruction_simplifier (after) + /// CHECK-DAG: And + public static byte $noinline$redundantAndNotRedundant(int value) { + // Here the AND is not redundant. This test checks that it is not removed. + // 0xf500 = 1111 0101 0000 0000 - bits [11:8] of value will be changed by + // the AND with 0101. These bits are kept following the SHR and TypeConversion. + return (byte) ((value & 0xf500) >> 8); + } + + /// CHECK-START: byte Main.$noinline$redundantAndOtherUse(int) instruction_simplifier (before) + /// CHECK-DAG: And + + /// CHECK-START: byte Main.$noinline$redundantAndOtherUse(int) instruction_simplifier (after) + /// CHECK-DAG: And + public static byte $noinline$redundantAndOtherUse(int value){ + int v1 = value & 0xff00; + // Above AND is redundant in the context of calculating v2. + byte v2 = (byte) (v1 >> 8); + byte v3 = (byte) (v1 - 0x6eef); + // Use of AND result (v1) in calculating v3 means AND must not be removed. + return (byte) (v2 - v3); + } + + /// CHECK-START: byte Main.$noinline$redundantAndShortToByteShift2(short) instruction_simplifier (before) + /// CHECK-DAG: And + + /// CHECK-START: byte Main.$noinline$redundantAndShortToByteShift2(short) instruction_simplifier (after) + /// CHECK-NOT: And + public static byte $noinline$redundantAndShortToByteShift2(short value) { + // & 0xfff only changes bits higher than bit number 12 inclusive. + // These bits are discarded during Type Conversion to byte. + // Therefore AND is redundant and should be removed. + return (byte) ((value & 0xfff) >> 2); + } + + /// CHECK-START: byte Main.$noinline$redundantAndShortToByteShift5(short) instruction_simplifier (before) + /// CHECK-DAG: And + + /// CHECK-START: byte Main.$noinline$redundantAndShortToByteShift5(short) instruction_simplifier (after) + /// CHECK-NOT: And + public static byte $noinline$redundantAndShortToByteShift5(short value) { + // & 0xffe0 changes bits [4:0] and bits higher than 16 inclusive. + // These bits are discarded by the right shift and type conversion. + // Therefore AND is redundant and should be removed. + return (byte) ((value & 0xffe0) >> 5); + } + + /// CHECK-START: byte Main.$noinline$redundantAndShortToByteShift8(short) instruction_simplifier (before) + /// CHECK-DAG: And + + /// CHECK-START: byte Main.$noinline$redundantAndShortToByteShift8(short) instruction_simplifier (after) + /// CHECK-NOT: And + public static byte $noinline$redundantAndShortToByteShift8(short value) { + return (byte) ((value & 0xff00) >> 8); + } + + /// CHECK-START: byte Main.$noinline$redundantAndShortToByteShift9NotRedundant(short) instruction_simplifier (before) + /// CHECK-DAG: And + + /// CHECK-START: byte Main.$noinline$redundantAndShortToByteShift9NotRedundant(short) instruction_simplifier (after) + /// CHECK-DAG: And + public static byte $noinline$redundantAndShortToByteShift9NotRedundant(short value) { + // Byte and Short operands for bitwise operations (e.g. &,>>) are promoted to Int32 prior to operation. + // Negative operands will be sign extended accordingly: (short: 0xff45) --> (int: 0xffffff45) + // & fe00 will clear bits [31:16]. For negative 'value', this will clear sign bits. + // Without the AND, the right shift will move the sign extended ones into the result instead of zeros. + // Therefore AND is not redundant and should not be removed. + return (byte) ((value & 0xfe00) >> 9); + } + + /// CHECK-START: byte Main.$noinline$redundantAndShortToByteShift10NotRedundant(short) instruction_simplifier (before) + /// CHECK-DAG: And + + /// CHECK-START: byte Main.$noinline$redundantAndShortToByteShift10NotRedundant(short) instruction_simplifier (after) + /// CHECK-DAG: And + public static byte $noinline$redundantAndShortToByteShift10NotRedundant(short value) { + return (byte) ((value & 0x1ffff) >> 10); + } + + /// CHECK-START: byte Main.$noinline$redundantAndShortToByteShift12(short) instruction_simplifier (before) + /// CHECK-DAG: And + + /// CHECK-START: byte Main.$noinline$redundantAndShortToByteShift12(short) instruction_simplifier (after) + /// CHECK-NOT: And + public static byte $noinline$redundantAndShortToByteShift12(short value) { + // & fff00 preserves bits [19:8] and clears all others. + // Here the AND preserves enough ones; such that zeros are moved into the result. + // Therefore AND is redundant and can be removed. + return (byte) ((value & 0xfff00) >> 12); + } + + /// CHECK-START: byte Main.$noinline$redundantAndShortToByteShift15(short) instruction_simplifier (before) + /// CHECK-DAG: And + + /// CHECK-START: byte Main.$noinline$redundantAndShortToByteShift15(short) instruction_simplifier (after) + /// CHECK-NOT: And + public static byte $noinline$redundantAndShortToByteShift15(short value) { + return (byte) ((value & 0xffff00) >> 15); + } + + /// CHECK-START: byte Main.$noinline$redundantAndShortToByteShift16(short) instruction_simplifier (before) + /// CHECK-DAG: And + + /// CHECK-START: byte Main.$noinline$redundantAndShortToByteShift16(short) instruction_simplifier (after) + /// CHECK-NOT: And + public static byte $noinline$redundantAndShortToByteShift16(short value) { + return (byte) ((value & 0xf0ffff00) >> 16); + } + + /// CHECK-START: byte Main.$noinline$redundantAndIntToByteShift2(int) instruction_simplifier (before) + /// CHECK-DAG: And + + /// CHECK-START: byte Main.$noinline$redundantAndIntToByteShift2(int) instruction_simplifier (after) + /// CHECK-NOT: And + public static byte $noinline$redundantAndIntToByteShift2(int value) { + return (byte) ((value & 0xfff) >> 2); + } + + /// CHECK-START: byte Main.$noinline$redundantAndIntToByteShift5(int) instruction_simplifier (before) + /// CHECK-DAG: And + + /// CHECK-START: byte Main.$noinline$redundantAndIntToByteShift5(int) instruction_simplifier (after) + /// CHECK-NOT: And + public static byte $noinline$redundantAndIntToByteShift5(int value) { + return (byte) ((value & 0xffe0) >> 5); + } + + /// CHECK-START: byte Main.$noinline$redundantAndIntToByteShift8(int) instruction_simplifier (before) + /// CHECK-DAG: And + + /// CHECK-START: byte Main.$noinline$redundantAndIntToByteShift8(int) instruction_simplifier (after) + /// CHECK-NOT: And + public static byte $noinline$redundantAndIntToByteShift8(int value) { + return (byte) ((value & 0xffffff00) >> 8); + } + + /// CHECK-START: byte Main.$noinline$redundantAndIntToByteShift9(int) instruction_simplifier (before) + /// CHECK-DAG: And + + /// CHECK-START: byte Main.$noinline$redundantAndIntToByteShift9(int) instruction_simplifier (after) + /// CHECK-NOT: And + public static byte $noinline$redundantAndIntToByteShift9(int value) { + return (byte) ((value & 0xf001fe00) >> 9); + } + + /// CHECK-START: byte Main.$noinline$redundantAndIntToByteShift16(int) instruction_simplifier (before) + /// CHECK-DAG: And + + /// CHECK-START: byte Main.$noinline$redundantAndIntToByteShift16(int) instruction_simplifier (after) + /// CHECK-NOT: And + public static byte $noinline$redundantAndIntToByteShift16(int value) { + return (byte) ((value & 0xf0ff0000) >> 16); + } + + /// CHECK-START: byte Main.$noinline$redundantAndIntToByteShift20(int) instruction_simplifier (before) + /// CHECK-DAG: And + + /// CHECK-START: byte Main.$noinline$redundantAndIntToByteShift20(int) instruction_simplifier (after) + /// CHECK-NOT: And + public static byte $noinline$redundantAndIntToByteShift20(int value) { + return (byte) ((value & 0xfff00000) >> 20); + } + + /// CHECK-START: byte Main.$noinline$redundantAndIntToByteShift25(int) instruction_simplifier (before) + /// CHECK-DAG: And + + /// CHECK-START: byte Main.$noinline$redundantAndIntToByteShift25(int) instruction_simplifier (after) + /// CHECK-NOT: And + public static byte $noinline$redundantAndIntToByteShift25(int value) { + return (byte) ((value & 0xfe000000) >> 25); + } + + /// CHECK-START: byte Main.$noinline$redundantAndIntToByteShift24(int) instruction_simplifier (before) + /// CHECK-DAG: And + + /// CHECK-START: byte Main.$noinline$redundantAndIntToByteShift24(int) instruction_simplifier (after) + /// CHECK-NOT: And + public static byte $noinline$redundantAndIntToByteShift24(int value) { + return (byte) ((value & 0xff000000) >> 24); + } + + /// CHECK-START: byte Main.$noinline$redundantAndIntToByteShift31(int) instruction_simplifier (before) + /// CHECK-DAG: And + + /// CHECK-START: byte Main.$noinline$redundantAndIntToByteShift31(int) instruction_simplifier (after) + /// CHECK-NOT: And + public static byte $noinline$redundantAndIntToByteShift31(int value) { + return (byte) ((value & 0xff000000) >> 31); + } + + /// CHECK-START: byte Main.$noinline$redundantAndShortToByteShortAndConstant(short) instruction_simplifier (before) + /// CHECK-DAG: And + + /// CHECK-START: byte Main.$noinline$redundantAndShortToByteShortAndConstant(short) instruction_simplifier (after) + /// CHECK-NOT: And + public static byte $noinline$redundantAndShortToByteShortAndConstant(short value) { + short and_constant = (short) 0xff00; + return (byte) ((value & and_constant) >> 16); + } + + /// CHECK-START: byte Main.$noinline$redundantAndIntToByteShortAndConstant(int) instruction_simplifier (before) + /// CHECK-DAG: And + + /// CHECK-START: byte Main.$noinline$redundantAndIntToByteShortAndConstant(int) instruction_simplifier (after) + /// CHECK-NOT: And + public static byte $noinline$redundantAndIntToByteShortAndConstant(int value) { + short and_constant = (short) 0xff00; + return (byte) ((value & and_constant) >> 16); + } + public static void main(String[] args) throws Exception { Class smaliTests2 = Class.forName("SmaliTests2"); Method $noinline$XorAllOnes = smaliTests2.getMethod("$noinline$XorAllOnes", int.class); @@ -2793,6 +3006,48 @@ public class Main { assertIntEquals(0, $noinline$singleCharStringIndexOfAfter('x', -1)); assertIntEquals(-1, $noinline$singleCharStringIndexOfAfter('x', 1)); assertIntEquals(-1, $noinline$singleCharStringIndexOfAfter('Z', -1)); + + assertIntEquals(0x65,$noinline$redundantAndNotRedundant(0x7fff6f45)); + assertIntEquals(0x5e,$noinline$redundantAndOtherUse(0x7fff6f45)); + + assertIntEquals(0x79, $noinline$redundantAndShortToByteShift2((short) 0x6de7)); + assertIntEquals(0x79, $noinline$redundantAndShortToByteShift2((short) 0xfde7)); + assertIntEquals(0x7a, $noinline$redundantAndShortToByteShift5((short) 0x6f45)); + assertIntEquals(-6, $noinline$redundantAndShortToByteShift5((short) 0xff45)); + assertIntEquals(0x6f, $noinline$redundantAndShortToByteShift8((short) 0x6f45)); + assertIntEquals(-1, $noinline$redundantAndShortToByteShift8((short) 0xff45)); + assertIntEquals(0x37, $noinline$redundantAndShortToByteShift9NotRedundant((short) 0x6f45)); + assertIntEquals(127, $noinline$redundantAndShortToByteShift9NotRedundant((short) 0xff45)); + assertIntEquals(127, $noinline$redundantAndShortToByteShift10NotRedundant((short) 0xffff)); + assertIntEquals(6, $noinline$redundantAndShortToByteShift12((short) 0x6f45)); + assertIntEquals(-1, $noinline$redundantAndShortToByteShift12((short) 0xff45)); + assertIntEquals(0, $noinline$redundantAndShortToByteShift15((short) 0x6f45)); + assertIntEquals(-1, $noinline$redundantAndShortToByteShift15((short) 0xff45)); + assertIntEquals(0, $noinline$redundantAndShortToByteShift16((short) 0x6f45)); + assertIntEquals(-1, $noinline$redundantAndShortToByteShift16((short) 0xff45)); + assertIntEquals(0, $noinline$redundantAndShortToByteShortAndConstant((short) 0x6f45)); + assertIntEquals(-1, $noinline$redundantAndShortToByteShortAndConstant((short) 0xff45)); + + assertIntEquals(0x79, $noinline$redundantAndIntToByteShift2(0x7fff6de7)); + assertIntEquals(0x79, $noinline$redundantAndIntToByteShift2(0xfffffde7)); + assertIntEquals(0x7a, $noinline$redundantAndIntToByteShift5(0x7fff6f45)); + assertIntEquals(-6, $noinline$redundantAndIntToByteShift5(0xffffff45)); + assertIntEquals(0x6f, $noinline$redundantAndIntToByteShift8(0x7fff6f45)); + assertIntEquals(-1, $noinline$redundantAndIntToByteShift8(0xffffff45)); + assertIntEquals(-73, $noinline$redundantAndIntToByteShift9(0x7fff6f45)); + assertIntEquals(-1, $noinline$redundantAndIntToByteShift9(0xffffff45)); + assertIntEquals(0x6f, $noinline$redundantAndIntToByteShift16(0x7f6fffff)); + assertIntEquals(0x6f, $noinline$redundantAndIntToByteShift16(0xff6fff45)); + assertIntEquals(0x6f, $noinline$redundantAndIntToByteShift20(0x76ffffff)); + assertIntEquals(0x6f, $noinline$redundantAndIntToByteShift20(0xf6ffff45)); + assertIntEquals(0x7f, $noinline$redundantAndIntToByteShift24(0x7fffffff)); + assertIntEquals(-1, $noinline$redundantAndIntToByteShift24(0xffffff45)); + assertIntEquals(0x3f, $noinline$redundantAndIntToByteShift25(0x7fffffff)); + assertIntEquals(-1, $noinline$redundantAndIntToByteShift25(0xffffff45)); + assertIntEquals(0, $noinline$redundantAndIntToByteShift31(0x7fffffff)); + assertIntEquals(-1, $noinline$redundantAndIntToByteShift31(0xffffff45)); + assertIntEquals(-1, $noinline$redundantAndIntToByteShortAndConstant(0x7fffff45)); + assertIntEquals(-1, $noinline$redundantAndIntToByteShortAndConstant(0xffffff45)); } private static boolean $inline$true() { return true; } |