diff --git a/src/hotspot/share/opto/superword.cpp b/src/hotspot/share/opto/superword.cpp
index 8c1e0351649c9d1f964ca01198706b4e2c329f48..779e5b3cbe72941237a1bcc95cf70764e8deac74 100644
--- a/src/hotspot/share/opto/superword.cpp
+++ b/src/hotspot/share/opto/superword.cpp
@@ -4228,11 +4228,42 @@ bool SWPointer::scaled_iv_plus_offset(Node* n) {
}
} else if (opc == Op_SubI) {
if (offset_plus_k(n->in(2), true) && scaled_iv_plus_offset(n->in(1))) {
+ // (offset1 + invar1 + scale * iv) - (offset2) or
+ // (offset1 + scale * iv) - (offset2 + invar1)
+ // Subtraction handled via "negate" flag of "offset_plus_k".
NOT_PRODUCT(_tracer.scaled_iv_plus_offset_6(n);)
return true;
}
- if (offset_plus_k(n->in(1)) && scaled_iv_plus_offset(n->in(2))) {
- _scale *= -1;
+ SWPointer tmp(this);
+ if (offset_plus_k(n->in(1)) && tmp.scaled_iv_plus_offset(n->in(2))) {
+ // (offset1 + invar1) - (offset2 + scale * iv) or
+ // (offset1) - (offset2 + invar1 + scale * iv)
+ // Subtraction handled explicitly below.
+ assert(_scale == 0, "shouldn't be set yet");
+ // _scale = -tmp._scale
+ if (!try_MulI_no_overflow(-1, tmp._scale, _scale)) {
+ return false; // mul overflow.
+ }
+ // _offset -= tmp._offset
+ if (!try_SubI_no_overflow(_offset, tmp._offset, _offset)) {
+ return false; // sub overflow.
+ }
+ // _invar -= tmp._invar
+ if (tmp._invar != nullptr) {
+ if (_invar != nullptr) {
+ return false;
+ }
+ _invar = tmp._invar;
+ _invar_scale = tmp._invar_scale;
+ _negate_invar = !tmp._negate_invar;
+ }
+
+ // SWPointer tmp does not have an integer part to be forwarded
+ // (tmp._has_int_index_after_convI2L is false) because n is a SubI, all
+ // nodes above must also be of integer type (ConvL2I is not handled
+ // to allow a long) and ConvI2L (the only node that can add an integer
+ // part) won't be present.
+
NOT_PRODUCT(_tracer.scaled_iv_plus_offset_7(n);)
return true;
}
@@ -4275,7 +4306,9 @@ bool SWPointer::scaled_iv(Node* n) {
}
} else if (opc == Op_LShiftI) {
if (n->in(1) == iv() && n->in(2)->is_Con()) {
- _scale = 1 << n->in(2)->get_int();
+ if (!try_LShiftI_no_overflow(1, n->in(2)->get_int(), _scale)) {
+ return false; // shift overflow.
+ }
NOT_PRODUCT(_tracer.scaled_iv_6(n, _scale);)
return true;
}
@@ -4298,15 +4331,29 @@ bool SWPointer::scaled_iv(Node* n) {
if (tmp.scaled_iv_plus_offset(n->in(1)) && tmp.has_iv()) {
// We successfully matched an integer index, of the form:
// int_index = int_offset + int_invar + int_scale * iv
+ // Forward scale.
+ assert(_scale == 0 && tmp._scale != 0, "iv only found just now");
+ _scale = tmp._scale;
+ // Accumulate offset.
+ if (!try_AddI_no_overflow(_offset, tmp._offset, _offset)) {
+ return false; // add overflow.
+ }
+ // Forward invariant if not already found.
+ if (tmp._invar != nullptr) {
+ if (_invar != nullptr) {
+ return false;
+ }
+ _invar = tmp._invar;
+ _invar_scale = tmp._invar_scale;
+ _negate_invar = tmp._negate_invar;
+ }
+ // Set info about the int_index:
+ assert(!_has_int_index_after_convI2L, "no previous int_index discovered");
_has_int_index_after_convI2L = true;
_int_index_after_convI2L_offset = tmp._offset;
_int_index_after_convI2L_invar = tmp._invar;
_int_index_after_convI2L_scale = tmp._scale;
- }
- // Now parse it again for the real SWPointer. This makes sure that the int_offset, int_invar,
- // and int_scale are properly added to the final SWPointer's offset, invar, and scale.
- if (scaled_iv_plus_offset(n->in(1))) {
NOT_PRODUCT(_tracer.scaled_iv_7(n);)
return true;
}
@@ -4325,12 +4372,14 @@ bool SWPointer::scaled_iv(Node* n) {
NOT_PRODUCT(_tracer.scaled_iv_8(n, &tmp);)
if (tmp.scaled_iv_plus_offset(n->in(1))) {
- int scale = n->in(2)->get_int();
+ int shift = n->in(2)->get_int();
// Accumulate scale.
- _scale = tmp._scale << scale;
+ if (!try_LShiftI_no_overflow(tmp._scale, shift, _scale)) {
+ return false; // shift overflow.
+ }
// Accumulate offset.
int shifted_offset = 0;
- if (!try_LShiftI_no_overflow(tmp._offset, scale, shifted_offset)) {
+ if (!try_LShiftI_no_overflow(tmp._offset, shift, shifted_offset)) {
return false; // shift overflow.
}
if (!try_AddI_no_overflow(_offset, shifted_offset, _offset)) {
@@ -4344,6 +4393,7 @@ bool SWPointer::scaled_iv(Node* n) {
}
// Forward info about the int_index:
+ assert(!_has_int_index_after_convI2L, "no previous int_index discovered");
_has_int_index_after_convI2L = tmp._has_int_index_after_convI2L;
_int_index_after_convI2L_offset = tmp._int_index_after_convI2L_offset;
_int_index_after_convI2L_invar = tmp._int_index_after_convI2L_invar;
@@ -4486,6 +4536,9 @@ bool SWPointer::try_AddSubI_no_overflow(int offset1, int offset2, bool is_sub, i
}
bool SWPointer::try_LShiftI_no_overflow(int offset, int shift, int& result) {
+ if (shift < 0 || shift > 31) {
+ return false;
+ }
jlong long_offset = java_shift_left((jlong)(offset), (julong)((jlong)(shift)));
jint int_offset = java_shift_left((jint)(offset), (juint)((jint)(shift)));
if (long_offset != int_offset) {
@@ -4495,6 +4548,16 @@ bool SWPointer::try_LShiftI_no_overflow(int offset, int shift, int& result) {
return true;
}
+bool SWPointer::try_MulI_no_overflow(int offset1, int offset2, int& result) {
+ jlong long_offset = java_multiply((jlong)(offset1), (jlong)(offset2));
+ jint int_offset = java_multiply((jint)(offset1), (jint)(offset2));
+ if (long_offset != int_offset) {
+ return false;
+ }
+ result = int_offset;
+ return true;
+}
+
//----------------------------print------------------------
void SWPointer::print() {
#ifndef PRODUCT
diff --git a/src/hotspot/share/opto/superword.hpp b/src/hotspot/share/opto/superword.hpp
index bb7f8b72997713a3036dd3b5d8e5b757fd3e5bb7..5d95a14cd065695692dd2c439d41b6ea20807d15 100644
--- a/src/hotspot/share/opto/superword.hpp
+++ b/src/hotspot/share/opto/superword.hpp
@@ -814,6 +814,7 @@ class SWPointer {
static bool try_SubI_no_overflow(int offset1, int offset2, int& result);
static bool try_AddSubI_no_overflow(int offset1, int offset2, bool is_sub, int& result);
static bool try_LShiftI_no_overflow(int offset1, int offset2, int& result);
+ static bool try_MulI_no_overflow(int offset1, int offset2, int& result);
};