--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/asm/assembler.cpp Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,273 @@
+/*
+ * Copyright 1997-2006 Sun Microsystems, Inc. All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+#include "incls/_precompiled.incl"
+#include "incls/_assembler.cpp.incl"
+
+
+// Implementation of AbstractAssembler
+//
+// The AbstractAssembler is generating code into a CodeBuffer. To make code generation faster,
+// the assembler keeps a copy of the code buffers boundaries & modifies them when
+// emitting bytes rather than using the code buffers accessor functions all the time.
+// The code buffer is updated via set_code_end(...) after emiting a whole instruction.
+
+AbstractAssembler::AbstractAssembler(CodeBuffer* code) {
+ if (code == NULL) return;
+ CodeSection* cs = code->insts();
+ cs->clear_mark(); // new assembler kills old mark
+ _code_section = cs;
+ _code_begin = cs->start();
+ _code_limit = cs->limit();
+ _code_pos = cs->end();
+ _oop_recorder= code->oop_recorder();
+ if (_code_begin == NULL) {
+ vm_exit_out_of_memory1(0, "CodeCache: no room for %s", code->name());
+ }
+}
+
+void AbstractAssembler::set_code_section(CodeSection* cs) {
+ assert(cs->outer() == code_section()->outer(), "sanity");
+ assert(cs->is_allocated(), "need to pre-allocate this section");
+ cs->clear_mark(); // new assembly into this section kills old mark
+ _code_section = cs;
+ _code_begin = cs->start();
+ _code_limit = cs->limit();
+ _code_pos = cs->end();
+}
+
+// Inform CodeBuffer that incoming code and relocation will be for stubs
+address AbstractAssembler::start_a_stub(int required_space) {
+ CodeBuffer* cb = code();
+ CodeSection* cs = cb->stubs();
+ assert(_code_section == cb->insts(), "not in insts?");
+ sync();
+ if (cs->maybe_expand_to_ensure_remaining(required_space)
+ && cb->blob() == NULL) {
+ return NULL;
+ }
+ set_code_section(cs);
+ return pc();
+}
+
+// Inform CodeBuffer that incoming code and relocation will be code
+// Should not be called if start_a_stub() returned NULL
+void AbstractAssembler::end_a_stub() {
+ assert(_code_section == code()->stubs(), "not in stubs?");
+ sync();
+ set_code_section(code()->insts());
+}
+
+// Inform CodeBuffer that incoming code and relocation will be for stubs
+address AbstractAssembler::start_a_const(int required_space, int required_align) {
+ CodeBuffer* cb = code();
+ CodeSection* cs = cb->consts();
+ assert(_code_section == cb->insts(), "not in insts?");
+ sync();
+ address end = cs->end();
+ int pad = -(intptr_t)end & (required_align-1);
+ if (cs->maybe_expand_to_ensure_remaining(pad + required_space)) {
+ if (cb->blob() == NULL) return NULL;
+ end = cs->end(); // refresh pointer
+ }
+ if (pad > 0) {
+ while (--pad >= 0) { *end++ = 0; }
+ cs->set_end(end);
+ }
+ set_code_section(cs);
+ return end;
+}
+
+// Inform CodeBuffer that incoming code and relocation will be code
+// Should not be called if start_a_const() returned NULL
+void AbstractAssembler::end_a_const() {
+ assert(_code_section == code()->consts(), "not in consts?");
+ sync();
+ set_code_section(code()->insts());
+}
+
+
+void AbstractAssembler::flush() {
+ sync();
+ ICache::invalidate_range(addr_at(0), offset());
+}
+
+
+void AbstractAssembler::a_byte(int x) {
+ emit_byte(x);
+}
+
+
+void AbstractAssembler::a_long(jint x) {
+ emit_long(x);
+}
+
+// Labels refer to positions in the (to be) generated code. There are bound
+// and unbound
+//
+// Bound labels refer to known positions in the already generated code.
+// offset() is the position the label refers to.
+//
+// Unbound labels refer to unknown positions in the code to be generated; it
+// may contain a list of unresolved displacements that refer to it
+#ifndef PRODUCT
+void AbstractAssembler::print(Label& L) {
+ if (L.is_bound()) {
+ tty->print_cr("bound label to %d|%d", L.loc_pos(), L.loc_sect());
+ } else if (L.is_unbound()) {
+ L.print_instructions((MacroAssembler*)this);
+ } else {
+ tty->print_cr("label in inconsistent state (loc = %d)", L.loc());
+ }
+}
+#endif // PRODUCT
+
+
+void AbstractAssembler::bind(Label& L) {
+ if (L.is_bound()) {
+ // Assembler can bind a label more than once to the same place.
+ guarantee(L.loc() == locator(), "attempt to redefine label");
+ return;
+ }
+ L.bind_loc(locator());
+ L.patch_instructions((MacroAssembler*)this);
+}
+
+void AbstractAssembler::generate_stack_overflow_check( int frame_size_in_bytes) {
+ if (UseStackBanging) {
+ // Each code entry causes one stack bang n pages down the stack where n
+ // is configurable by StackBangPages. The setting depends on the maximum
+ // depth of VM call stack or native before going back into java code,
+ // since only java code can raise a stack overflow exception using the
+ // stack banging mechanism. The VM and native code does not detect stack
+ // overflow.
+ // The code in JavaCalls::call() checks that there is at least n pages
+ // available, so all entry code needs to do is bang once for the end of
+ // this shadow zone.
+ // The entry code may need to bang additional pages if the framesize
+ // is greater than a page.
+
+ const int page_size = os::vm_page_size();
+ int bang_end = StackShadowPages*page_size;
+
+ // This is how far the previous frame's stack banging extended.
+ const int bang_end_safe = bang_end;
+
+ if (frame_size_in_bytes > page_size) {
+ bang_end += frame_size_in_bytes;
+ }
+
+ int bang_offset = bang_end_safe;
+ while (bang_offset <= bang_end) {
+ // Need at least one stack bang at end of shadow zone.
+ bang_stack_with_offset(bang_offset);
+ bang_offset += page_size;
+ }
+ } // end (UseStackBanging)
+}
+
+void Label::add_patch_at(CodeBuffer* cb, int branch_loc) {
+ assert(_loc == -1, "Label is unbound");
+ if (_patch_index < PatchCacheSize) {
+ _patches[_patch_index] = branch_loc;
+ } else {
+ if (_patch_overflow == NULL) {
+ _patch_overflow = cb->create_patch_overflow();
+ }
+ _patch_overflow->push(branch_loc);
+ }
+ ++_patch_index;
+}
+
+void Label::patch_instructions(MacroAssembler* masm) {
+ assert(is_bound(), "Label is bound");
+ CodeBuffer* cb = masm->code();
+ int target_sect = CodeBuffer::locator_sect(loc());
+ address target = cb->locator_address(loc());
+ while (_patch_index > 0) {
+ --_patch_index;
+ int branch_loc;
+ if (_patch_index >= PatchCacheSize) {
+ branch_loc = _patch_overflow->pop();
+ } else {
+ branch_loc = _patches[_patch_index];
+ }
+ int branch_sect = CodeBuffer::locator_sect(branch_loc);
+ address branch = cb->locator_address(branch_loc);
+ if (branch_sect == CodeBuffer::SECT_CONSTS) {
+ // The thing to patch is a constant word.
+ *(address*)branch = target;
+ continue;
+ }
+
+#ifdef ASSERT
+ // Cross-section branches only work if the
+ // intermediate section boundaries are frozen.
+ if (target_sect != branch_sect) {
+ for (int n = MIN2(target_sect, branch_sect),
+ nlimit = (target_sect + branch_sect) - n;
+ n < nlimit; n++) {
+ CodeSection* cs = cb->code_section(n);
+ assert(cs->is_frozen(), "cross-section branch needs stable offsets");
+ }
+ }
+#endif //ASSERT
+
+ // Push the target offset into the branch instruction.
+ masm->pd_patch_instruction(branch, target);
+ }
+}
+
+
+void AbstractAssembler::block_comment(const char* comment) {
+ if (sect() == CodeBuffer::SECT_INSTS) {
+ code_section()->outer()->block_comment(offset(), comment);
+ }
+}
+
+
+#ifndef PRODUCT
+void Label::print_instructions(MacroAssembler* masm) const {
+ CodeBuffer* cb = masm->code();
+ for (int i = 0; i < _patch_index; ++i) {
+ int branch_loc;
+ if (i >= PatchCacheSize) {
+ branch_loc = _patch_overflow->at(i - PatchCacheSize);
+ } else {
+ branch_loc = _patches[i];
+ }
+ int branch_pos = CodeBuffer::locator_pos(branch_loc);
+ int branch_sect = CodeBuffer::locator_sect(branch_loc);
+ address branch = cb->locator_address(branch_loc);
+ tty->print_cr("unbound label");
+ tty->print("@ %d|%d ", branch_pos, branch_sect);
+ if (branch_sect == CodeBuffer::SECT_CONSTS) {
+ tty->print_cr(PTR_FORMAT, *(address*)branch);
+ continue;
+ }
+ masm->pd_print_patched_instruction(branch);
+ tty->cr();
+ }
+}
+#endif // ndef PRODUCT