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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 00:47:55 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 00:47:55 +0000
commit26a029d407be480d791972afb5975cf62c9360a6 (patch)
treef435a8308119effd964b339f76abb83a57c29483 /js/src/jit/StackSlotAllocator.h
parentInitial commit. (diff)
downloadfirefox-26a029d407be480d791972afb5975cf62c9360a6.tar.xz
firefox-26a029d407be480d791972afb5975cf62c9360a6.zip
Adding upstream version 124.0.1.upstream/124.0.1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'js/src/jit/StackSlotAllocator.h')
-rw-r--r--js/src/jit/StackSlotAllocator.h135
1 files changed, 135 insertions, 0 deletions
diff --git a/js/src/jit/StackSlotAllocator.h b/js/src/jit/StackSlotAllocator.h
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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: set ts=8 sts=2 et sw=2 tw=80:
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef jit_StackSlotAllocator_h
+#define jit_StackSlotAllocator_h
+
+#include "jit/Registers.h"
+
+namespace js {
+namespace jit {
+
+class StackSlotAllocator {
+ js::Vector<uint32_t, 4, SystemAllocPolicy> normalSlots;
+ js::Vector<uint32_t, 4, SystemAllocPolicy> doubleSlots;
+ uint32_t height_;
+
+ void addAvailableSlot(uint32_t index) {
+ // Ignoring OOM here (and below) is fine; it just means the stack slot
+ // will be unused.
+ (void)normalSlots.append(index);
+ }
+ void addAvailableDoubleSlot(uint32_t index) {
+ (void)doubleSlots.append(index);
+ }
+
+ uint32_t allocateQuadSlot() {
+ // This relies on the fact that any architecture specific
+ // alignment of the stack pointer is done a priori.
+ if (height_ % 8 != 0) {
+ addAvailableSlot(height_ += 4);
+ }
+ if (height_ % 16 != 0) {
+ addAvailableDoubleSlot(height_ += 8);
+ }
+ return height_ += 16;
+ }
+ uint32_t allocateDoubleSlot() {
+ if (!doubleSlots.empty()) {
+ return doubleSlots.popCopy();
+ }
+ if (height_ % 8 != 0) {
+ addAvailableSlot(height_ += 4);
+ }
+ return height_ += 8;
+ }
+ uint32_t allocateSlot() {
+ if (!normalSlots.empty()) {
+ return normalSlots.popCopy();
+ }
+ if (!doubleSlots.empty()) {
+ uint32_t index = doubleSlots.popCopy();
+ addAvailableSlot(index - 4);
+ return index;
+ }
+ return height_ += 4;
+ }
+
+ public:
+ StackSlotAllocator() : height_(0) {}
+
+ void allocateStackArea(LStackArea* alloc) {
+ uint32_t size = alloc->size();
+
+ MOZ_ASSERT(size % 4 == 0);
+ switch (alloc->alignment()) {
+ case 8:
+ if ((height_ + size) % 8 != 0) {
+ addAvailableSlot(height_ += 4);
+ }
+ break;
+ default:
+ MOZ_CRASH("unexpected stack results area alignment");
+ }
+ MOZ_ASSERT((height_ + size) % alloc->alignment() == 0);
+
+ height_ += size;
+ alloc->setBase(height_);
+ }
+
+ static uint32_t width(LDefinition::Type type) {
+ switch (type) {
+#if JS_BITS_PER_WORD == 32
+ case LDefinition::GENERAL:
+ case LDefinition::OBJECT:
+ case LDefinition::SLOTS:
+ case LDefinition::WASM_ANYREF:
+#endif
+#ifdef JS_NUNBOX32
+ case LDefinition::TYPE:
+ case LDefinition::PAYLOAD:
+#endif
+ case LDefinition::INT32:
+ case LDefinition::FLOAT32:
+ return 4;
+#if JS_BITS_PER_WORD == 64
+ case LDefinition::GENERAL:
+ case LDefinition::OBJECT:
+ case LDefinition::SLOTS:
+ case LDefinition::WASM_ANYREF:
+#endif
+#ifdef JS_PUNBOX64
+ case LDefinition::BOX:
+#endif
+ case LDefinition::DOUBLE:
+ return 8;
+ case LDefinition::SIMD128:
+ return 16;
+ case LDefinition::STACKRESULTS:
+ MOZ_CRASH("Stack results area must be allocated manually");
+ }
+ MOZ_CRASH("Unknown slot type");
+ }
+
+ uint32_t allocateSlot(LDefinition::Type type) {
+ switch (width(type)) {
+ case 4:
+ return allocateSlot();
+ case 8:
+ return allocateDoubleSlot();
+ case 16:
+ return allocateQuadSlot();
+ }
+ MOZ_CRASH("Unknown slot width");
+ }
+
+ uint32_t stackHeight() const { return height_; }
+};
+
+} // namespace jit
+} // namespace js
+
+#endif /* jit_StackSlotAllocator_h */