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-rw-r--r--src/passes/MergeBlocks.cpp138
1 files changed, 78 insertions, 60 deletions
diff --git a/src/passes/MergeBlocks.cpp b/src/passes/MergeBlocks.cpp
index 38e9fc6a2..8df35abd2 100644
--- a/src/passes/MergeBlocks.cpp
+++ b/src/passes/MergeBlocks.cpp
@@ -72,21 +72,23 @@
// single outside block.
//
-#include <wasm.h>
-#include <pass.h>
-#include <wasm-builder.h>
#include <ir/branch-utils.h>
#include <ir/effects.h>
#include <ir/utils.h>
+#include <pass.h>
+#include <wasm-builder.h>
+#include <wasm.h>
namespace wasm {
// Looks for reasons we can't remove the values from breaks to an origin
-// For example, if there is a switch targeting us, we can't do it - we can't remove the value from other targets
+// For example, if there is a switch targeting us, we can't do it - we can't
+// remove the value from other targets
struct ProblemFinder : public ControlFlowWalker<ProblemFinder> {
Name origin;
bool foundProblem = false;
- // count br_ifs, and dropped br_ifs. if they don't match, then a br_if flow value is used, and we can't drop it
+ // count br_ifs, and dropped br_ifs. if they don't match, then a br_if flow
+ // value is used, and we can't drop it
Index brIfs = 0;
Index droppedBrIfs = 0;
PassOptions& passOptions;
@@ -158,8 +160,10 @@ struct BreakValueDropper : public ControlFlowWalker<BreakValueDropper> {
}
void visitDrop(Drop* curr) {
- // if we dropped a br_if whose value we removed, then we are now dropping a (block (drop value) (br_if)) with type none, which does not need a drop
- // likewise, unreachable does not need to be dropped, so we just leave drops of concrete values
+ // if we dropped a br_if whose value we removed, then we are now dropping a
+ // (block (drop value) (br_if)) with type none, which does not need a drop
+ // likewise, unreachable does not need to be dropped, so we just leave drops
+ // of concrete values
if (!isConcreteType(curr->value->type)) {
replaceCurrent(curr->value);
}
@@ -188,7 +192,8 @@ static bool hasDeadCode(Block* block) {
}
// core block optimizer routine
-static void optimizeBlock(Block* curr, Module* module, PassOptions& passOptions) {
+static void
+optimizeBlock(Block* curr, Module* module, PassOptions& passOptions) {
auto& list = curr->list;
// Main merging loop.
bool more = true;
@@ -205,7 +210,8 @@ static void optimizeBlock(Block* curr, Module* module, PassOptions& passOptions)
Loop* loop = nullptr;
// To to handle a non-block child.
if (!childBlock) {
- // if we have a child that is (drop (block ..)) then we can move the drop into the block, and remove br values. this allows more merging,
+ // if we have a child that is (drop (block ..)) then we can move the
+ // drop into the block, and remove br values. this allows more merging,
if (auto* drop = list[i]->dynCast<Drop>()) {
childBlock = drop->value->dynCast<Block>();
if (childBlock) {
@@ -253,13 +259,16 @@ static void optimizeBlock(Block* curr, Module* module, PassOptions& passOptions)
}
}
// If no block, we can't do anything.
- if (!childBlock) continue;
+ if (!childBlock)
+ continue;
auto& childList = childBlock->list;
auto childSize = childList.size();
- if (childSize == 0) continue;
- // If the child has items after an unreachable, ignore it - dce should have
- // been run, and we prefer to not handle the complexity here.
- if (hasDeadCode(childBlock)) continue;
+ if (childSize == 0)
+ continue;
+ // If the child has items after an unreachable, ignore it - dce should
+ // have been run, and we prefer to not handle the complexity here.
+ if (hasDeadCode(childBlock))
+ continue;
// In some cases we can remove only the head or the tail of the block,
// and must keep some things in the child block.
Index keepStart = childSize;
@@ -295,8 +304,9 @@ static void optimizeBlock(Block* curr, Module* module, PassOptions& passOptions)
break;
}
}
- // If we can only do part of the block, and if the block has a flowing value, we
- // would need special handling for that - not worth it, probably TODO
+ // If we can only do part of the block, and if the block has a flowing
+ // value, we would need special handling for that - not worth it,
+ // probably TODO
// FIXME is this not handled by the drop later down?
if (keepEnd < childSize && isConcreteType(childList.back()->type)) {
continue;
@@ -304,7 +314,8 @@ static void optimizeBlock(Block* curr, Module* module, PassOptions& passOptions)
}
// Maybe there's nothing to do, if we must keep it all in the
// child anyhow.
- if (keepStart == 0 && keepEnd == childSize) continue;
+ if (keepStart == 0 && keepEnd == childSize)
+ continue;
// There is something to do!
bool keepingPart = keepStart < keepEnd;
// Create a new merged list, and fill in the code before the
@@ -393,31 +404,45 @@ struct MergeBlocks : public WalkerPass<PostWalker<MergeBlocks>> {
// (..other..children..)
// )
// )
- // at which point the block is on the outside and potentially mergeable with an outer block
- Block* optimize(Expression* curr, Expression*& child, Block* outer = nullptr, Expression** dependency1 = nullptr, Expression** dependency2 = nullptr) {
- if (!child) return outer;
+ // at which point the block is on the outside and potentially mergeable with
+ // an outer block
+ Block* optimize(Expression* curr,
+ Expression*& child,
+ Block* outer = nullptr,
+ Expression** dependency1 = nullptr,
+ Expression** dependency2 = nullptr) {
+ if (!child)
+ return outer;
if ((dependency1 && *dependency1) || (dependency2 && *dependency2)) {
- // there are dependencies, things we must be reordered through. make sure no problems there
+ // there are dependencies, things we must be reordered through. make sure
+ // no problems there
EffectAnalyzer childEffects(getPassOptions(), child);
- if (dependency1 && *dependency1 && EffectAnalyzer(getPassOptions(), *dependency1).invalidates(childEffects)) return outer;
- if (dependency2 && *dependency2 && EffectAnalyzer(getPassOptions(), *dependency2).invalidates(childEffects)) return outer;
+ if (dependency1 && *dependency1 &&
+ EffectAnalyzer(getPassOptions(), *dependency1)
+ .invalidates(childEffects))
+ return outer;
+ if (dependency2 && *dependency2 &&
+ EffectAnalyzer(getPassOptions(), *dependency2)
+ .invalidates(childEffects))
+ return outer;
}
if (auto* block = child->dynCast<Block>()) {
if (!block->name.is() && block->list.size() >= 2) {
- // if we move around unreachable code, type changes could occur. avoid that, as
- // anyhow it means we should have run dce before getting here
+ // if we move around unreachable code, type changes could occur. avoid
+ // that, as anyhow it means we should have run dce before getting here
if (curr->type == none && hasUnreachableChild(block)) {
- // moving the block to the outside would replace a none with an unreachable
+ // moving the block to the outside would replace a none with an
+ // unreachable
return outer;
}
auto* back = block->list.back();
if (back->type == unreachable) {
- // curr is not reachable, dce could remove it; don't try anything fancy
- // here
+ // curr is not reachable, dce could remove it; don't try anything
+ // fancy here
return outer;
}
- // we are going to replace the block with the final element, so they should
- // be identically typed
+ // we are going to replace the block with the final element, so they
+ // should be identically typed
if (block->type != back->type) {
return outer;
}
@@ -443,18 +468,10 @@ struct MergeBlocks : public WalkerPass<PostWalker<MergeBlocks>> {
return outer;
}
- void visitUnary(Unary* curr) {
- optimize(curr, curr->value);
- }
- void visitSetLocal(SetLocal* curr) {
- optimize(curr, curr->value);
- }
- void visitLoad(Load* curr) {
- optimize(curr, curr->ptr);
- }
- void visitReturn(Return* curr) {
- optimize(curr, curr->value);
- }
+ void visitUnary(Unary* curr) { optimize(curr, curr->value); }
+ void visitSetLocal(SetLocal* curr) { optimize(curr, curr->value); }
+ void visitLoad(Load* curr) { optimize(curr, curr->ptr); }
+ void visitReturn(Return* curr) { optimize(curr, curr->value); }
void visitBinary(Binary* curr) {
optimize(curr, curr->right, optimize(curr, curr->left), &curr->left);
@@ -466,15 +483,20 @@ struct MergeBlocks : public WalkerPass<PostWalker<MergeBlocks>> {
optimize(curr, curr->value, optimize(curr, curr->ptr), &curr->ptr);
}
void optimizeTernary(Expression* curr,
- Expression*& first, Expression*& second, Expression*& third) {
+ Expression*& first,
+ Expression*& second,
+ Expression*& third) {
// TODO: for now, just stop when we see any side effect. instead, we could
// check effects carefully for reordering
Block* outer = nullptr;
- if (EffectAnalyzer(getPassOptions(), first).hasSideEffects()) return;
+ if (EffectAnalyzer(getPassOptions(), first).hasSideEffects())
+ return;
outer = optimize(curr, first, outer);
- if (EffectAnalyzer(getPassOptions(), second).hasSideEffects()) return;
+ if (EffectAnalyzer(getPassOptions(), second).hasSideEffects())
+ return;
outer = optimize(curr, second, outer);
- if (EffectAnalyzer(getPassOptions(), third).hasSideEffects()) return;
+ if (EffectAnalyzer(getPassOptions(), third).hasSideEffects())
+ return;
optimize(curr, third, outer);
}
void visitAtomicCmpxchg(AtomicCmpxchg* curr) {
@@ -485,9 +507,7 @@ struct MergeBlocks : public WalkerPass<PostWalker<MergeBlocks>> {
optimizeTernary(curr, curr->ifTrue, curr->ifFalse, curr->condition);
}
- void visitDrop(Drop* curr) {
- optimize(curr, curr->value);
- }
+ void visitDrop(Drop* curr) { optimize(curr, curr->value); }
void visitBreak(Break* curr) {
optimize(curr, curr->condition, optimize(curr, curr->value), &curr->value);
@@ -496,33 +516,31 @@ struct MergeBlocks : public WalkerPass<PostWalker<MergeBlocks>> {
optimize(curr, curr->condition, optimize(curr, curr->value), &curr->value);
}
- template<typename T>
- void handleCall(T* curr) {
+ template<typename T> void handleCall(T* curr) {
Block* outer = nullptr;
for (Index i = 0; i < curr->operands.size(); i++) {
- if (EffectAnalyzer(getPassOptions(), curr->operands[i]).hasSideEffects()) return;
+ if (EffectAnalyzer(getPassOptions(), curr->operands[i]).hasSideEffects())
+ return;
outer = optimize(curr, curr->operands[i], outer);
}
return;
}
- void visitCall(Call* curr) {
- handleCall(curr);
- }
+ void visitCall(Call* curr) { handleCall(curr); }
void visitCallIndirect(CallIndirect* curr) {
Block* outer = nullptr;
for (Index i = 0; i < curr->operands.size(); i++) {
- if (EffectAnalyzer(getPassOptions(), curr->operands[i]).hasSideEffects()) return;
+ if (EffectAnalyzer(getPassOptions(), curr->operands[i]).hasSideEffects())
+ return;
outer = optimize(curr, curr->operands[i], outer);
}
- if (EffectAnalyzer(getPassOptions(), curr->target).hasSideEffects()) return;
+ if (EffectAnalyzer(getPassOptions(), curr->target).hasSideEffects())
+ return;
optimize(curr, curr->target, outer);
}
};
-Pass *createMergeBlocksPass() {
- return new MergeBlocks();
-}
+Pass* createMergeBlocksPass() { return new MergeBlocks(); }
} // namespace wasm
generated by cgit v1.2.3 (git 2.39.1) at 2025-04-06 01:08:54 +0000