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8341415: Optimize RawBytecodeHelper::next

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Reviewed-by: liach
This commit is contained in:
Shaojin Wen 2024-10-03 12:08:23 +00:00
parent 6af13580c2
commit d7f32d891c
1 changed files with 26 additions and 31 deletions
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57
src/java.base/share/classes/jdk/internal/classfile/impl/RawBytecodeHelper.java
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@ -299,7 +299,6 @@ public final class RawBytecodeHelper {
private int nextBci;
private int bci;
private int opcode;
private boolean isWide;
public static CodeRange of(byte[] array) {
return new CodeRange(array, array.length);
@ -341,14 +340,14 @@ public final class RawBytecodeHelper {
* be valid and can be accessed unchecked.
*/
public int opcode() {
return opcode;
return opcode & 0xFF;
}
/**
* Returns whether the current functional opcode is in wide.
*/
public boolean isWide() {
return isWide;
return (opcode & (WIDE << 8)) != 0;
}
/**
@ -411,7 +410,7 @@ public final class RawBytecodeHelper {
// *load, *store, iinc
public int getIndex() {
return isWide ? getU2Unchecked(bci + 2) : getIndexU1();
return isWide() ? getU2Unchecked(bci + 2) : getIndexU1();
}
// ldc
@ -443,12 +442,11 @@ public final class RawBytecodeHelper {
int len = LENGTHS[code & 0xFF]; // & 0xFF eliminates bound check
this.bci = bci;
opcode = code;
isWide = false;
if (len <= 0) {
len = checkSpecialInstruction(bci, end, code); // sets opcode
}
if (len <= 0 || (nextBci += len) > end) {
if ((nextBci += len) > end) {
opcode = ILLEGAL;
}
@ -457,37 +455,34 @@ public final class RawBytecodeHelper {
// Put rarely used code in another method to reduce code size
private int checkSpecialInstruction(int bci, int end, int code) {
int len = -1;
if (code == WIDE) {
if (bci + 1 >= end) {
return -1;
if (bci + 1 < end) {
opcode = (WIDE << 8) | (code = getIndexU1());
// Validated in UtilTest.testOpcodeLengthTable
len = LENGTHS[code] * 2;
}
opcode = code = getIndexU1();
isWide = true;
// Validated in UtilTest.testOpcodeLengthTable
return LENGTHS[code] * 2;
}
if (code == TABLESWITCH) {
} else if (code == TABLESWITCH) {
int alignedBci = align(bci + 1);
if (alignedBci + 3 * 4 >= end) {
return -1;
if (alignedBci + 3 * 4 < end) {
int lo = getIntUnchecked(alignedBci + 1 * 4);
int hi = getIntUnchecked(alignedBci + 2 * 4);
long l = alignedBci - bci + (3L + (long) hi - lo + 1L) * 4L;
len = l > 0 && ((int) l == l) ? (int) l : -1;
}
int lo = getIntUnchecked(alignedBci + 1 * 4);
int hi = getIntUnchecked(alignedBci + 2 * 4);
long l = alignedBci - bci + (3L + (long) hi - lo + 1L) * 4L;
return l > 0 && ((int) l == l) ? (int) l : -1;
}
if (code == LOOKUPSWITCH) {
} else if (code == LOOKUPSWITCH) {
int alignedBci = align(bci + 1);
if (alignedBci + 2 * 4 >= end) {
return -1;
if (alignedBci + 2 * 4 < end) {
int npairs = getIntUnchecked(alignedBci + 4);
if (npairs >= 0) {
long l = alignedBci - bci + (2L + 2L * npairs) * 4L;
len = l > 0 && ((int) l == l) ? (int) l : -1;
}
}
int npairs = getIntUnchecked(alignedBci + 4);
if (npairs < 0) {
return -1;
}
long l = alignedBci - bci + (2L + 2L * npairs) * 4L;
return l > 0 && ((int) l == l) ? (int) l : -1;
}
return -1;
if (len <= 0) {
opcode = ILLEGAL;
}
return len;
}
}