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-rw-r--r--src/passes/RemoveUnusedBrs.cpp32
-rw-r--r--src/wasm-builder.h22
-rw-r--r--test/passes/remove-unused-brs.txt40
-rw-r--r--test/passes/remove-unused-brs.wast18
-rw-r--r--test/passes/remove-unused-names_remove-unused-brs_vacuum.txt18
-rw-r--r--test/passes/remove-unused-names_remove-unused-brs_vacuum.wast18
6 files changed, 116 insertions, 32 deletions
diff --git a/src/passes/RemoveUnusedBrs.cpp b/src/passes/RemoveUnusedBrs.cpp
index b725de901..3ab0371ed 100644
--- a/src/passes/RemoveUnusedBrs.cpp
+++ b/src/passes/RemoveUnusedBrs.cpp
@@ -232,11 +232,39 @@ struct RemoveUnusedBrs : public WalkerPass<PostWalker<RemoveUnusedBrs>> {
// this is already an if-else. if one side is a dead end, we can append to the other, if
// there is no returned value to concern us
assert(!isConcreteWasmType(iff->type)); // can't be, since in the middle of a block
+
+ // ensures the first node is a block, if it isn't already, and merges in the second,
+ // either as a single element or, if a block, by appending to the first block. this
+ // keeps the order of operations in place, that is, the appended element will be
+ // executed after the first node's elements
+ auto blockifyMerge = [&](Expression* any, Expression* append) -> Block* {
+ Block* block = nullptr;
+ if (any) block = any->dynCast<Block>();
+ // if the first isn't a block, or it's a block with a name (so we might
+ // branch to the end, and so can't append to it, we might skip that code!)
+ // then make a new block
+ if (!block || block->name.is()) {
+ block = builder.makeBlock(any);
+ } else {
+ assert(!isConcreteWasmType(block->type));
+ }
+ auto* other = append->dynCast<Block>();
+ if (!other) {
+ block->list.push_back(append);
+ } else {
+ for (auto* item : other->list) {
+ block->list.push_back(item);
+ }
+ }
+ block->finalize();
+ return block;
+ };
+
if (ExpressionAnalyzer::obviouslyDoesNotFlowOut(iff->ifTrue)) {
- iff->ifFalse = builder.blockifyMerge(iff->ifFalse, builder.stealSlice(block, i + 1, list.size()));
+ iff->ifFalse = blockifyMerge(iff->ifFalse, builder.stealSlice(block, i + 1, list.size()));
return true;
} else if (ExpressionAnalyzer::obviouslyDoesNotFlowOut(iff->ifFalse)) {
- iff->ifTrue = builder.blockifyMerge(iff->ifTrue, builder.stealSlice(block, i + 1, list.size()));
+ iff->ifTrue = blockifyMerge(iff->ifTrue, builder.stealSlice(block, i + 1, list.size()));
return true;
}
}
diff --git a/src/wasm-builder.h b/src/wasm-builder.h
index 41aaf6766..f702342d2 100644
--- a/src/wasm-builder.h
+++ b/src/wasm-builder.h
@@ -315,28 +315,6 @@ public:
return block;
}
- // ensures the first node is a block, if it isn't already, and merges in the second,
- // either as a single element or, if a block, by appending to the first block
- Block* blockifyMerge(Expression* any, Expression* append) {
- Block* block = nullptr;
- if (any) block = any->dynCast<Block>();
- if (!block) {
- block = makeBlock(any);
- } else {
- assert(!isConcreteWasmType(block->type));
- }
- auto* other = append->dynCast<Block>();
- if (!other) {
- block->list.push_back(append);
- } else {
- for (auto* item : other->list) {
- block->list.push_back(item);
- }
- }
- block->finalize();
- return block;
- }
-
// a helper for the common pattern of a sequence of two expressions. Similar to
// blockify, but does *not* reuse a block if the first is one.
Block* makeSequence(Expression* left, Expression* right) {
diff --git a/test/passes/remove-unused-brs.txt b/test/passes/remove-unused-brs.txt
index 07b4575ce..417bd3728 100644
--- a/test/passes/remove-unused-brs.txt
+++ b/test/passes/remove-unused-brs.txt
@@ -5,6 +5,7 @@
(type $3 (func (param i32 i32) (result i32)))
(type $4 (func (param i32 i32)))
(type $5 (func (param f32 i32 f32 i32 i32 f64 f32) (result i32)))
+ (type $6 (func (param i32) (result i64)))
(memory $0 256 256)
(func $b0-yes (type $0) (param $i1 i32)
(block $topmost
@@ -539,11 +540,13 @@
(block $out59
(if
(i32.const 0)
- (block $block61
- (drop
- (i32.const 1)
+ (block
+ (block $block61
+ (drop
+ (i32.const 1)
+ )
+ (call $loops)
)
- (call $loops)
(br $in58)
)
(nop)
@@ -584,11 +587,13 @@
(block $out69
(if
(i32.const 0)
- (block $block71
- (drop
- (i32.const 1)
+ (block
+ (block $block71
+ (drop
+ (i32.const 1)
+ )
+ (call $loops)
)
- (call $loops)
(drop
(i32.const 102)
)
@@ -1011,4 +1016,23 @@
(i32.const 1935947830)
)
)
+ (func $unexitable-loops-result (type $6) (param $0 i32) (result i64)
+ (loop $label$0
+ (loop $label$1
+ (br_if $label$0
+ (i32.load8_s
+ (i32.const 201460482)
+ )
+ )
+ (block
+ (block $label$3
+ (br_if $label$1
+ (get_local $0)
+ )
+ )
+ (br $label$1)
+ )
+ )
+ )
+ )
)
diff --git a/test/passes/remove-unused-brs.wast b/test/passes/remove-unused-brs.wast
index 04ebdac33..d694bd4d0 100644
--- a/test/passes/remove-unused-brs.wast
+++ b/test/passes/remove-unused-brs.wast
@@ -901,5 +901,23 @@
(i32.const 1935947830)
)
)
+ (func $unexitable-loops-result (param $0 i32) (result i64)
+ (loop $label$0
+ (loop $label$1
+ (if
+ (i32.load8_s
+ (i32.const 201460482)
+ )
+ (br $label$0)
+ (block $label$3
+ (br_if $label$3
+ (get_local $0)
+ )
+ )
+ )
+ (br $label$1)
+ )
+ )
+ )
)
diff --git a/test/passes/remove-unused-names_remove-unused-brs_vacuum.txt b/test/passes/remove-unused-names_remove-unused-brs_vacuum.txt
index d8ce15491..4eeb1ee97 100644
--- a/test/passes/remove-unused-names_remove-unused-brs_vacuum.txt
+++ b/test/passes/remove-unused-names_remove-unused-brs_vacuum.txt
@@ -22,6 +22,7 @@
(type $FUNCSIG$vii (func (param i32 i32)))
(type $FUNCSIG$iiii (func (param i32 i32 i32) (result i32)))
(type $FUNCSIG$id (func (param f64) (result i32)))
+ (type $23 (func (param i32) (result i64)))
(import "env" "DYNAMICTOP_PTR" (global $import$0 i32))
(import "env" "tempDoublePtr" (global $import$1 i32))
(import "env" "ABORT" (global $import$2 i32))
@@ -113,4 +114,21 @@
(func $23 (type $0) (param $0 i32) (param $1 i32) (param $2 i32) (result i32)
(unreachable)
)
+ (func $unexitable-loops-result (type $23) (param $0 i32) (result i64)
+ (loop $label$0
+ (loop $label$1
+ (br_if $label$0
+ (i32.load8_s
+ (i32.const 201460482)
+ )
+ )
+ (block
+ (br_if $label$1
+ (get_local $0)
+ )
+ (br $label$1)
+ )
+ )
+ )
+ )
)
diff --git a/test/passes/remove-unused-names_remove-unused-brs_vacuum.wast b/test/passes/remove-unused-names_remove-unused-brs_vacuum.wast
index 5a0ec5114..12f664a36 100644
--- a/test/passes/remove-unused-names_remove-unused-brs_vacuum.wast
+++ b/test/passes/remove-unused-names_remove-unused-brs_vacuum.wast
@@ -127,5 +127,23 @@
(func $23 (param i32) (param i32) (param i32) (result i32)
(unreachable)
)
+ (func $unexitable-loops-result (param $0 i32) (result i64)
+ (loop $label$0
+ (loop $label$1
+ (if
+ (i32.load8_s
+ (i32.const 201460482)
+ )
+ (br $label$0)
+ (block $label$3
+ (br_if $label$3
+ (get_local $0)
+ )
+ )
+ )
+ (br $label$1)
+ )
+ )
+ )
)
generated by cgit v1.2.3 (git 2.39.1) at 2025-08-05 05:19:47 +0000