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-rw-r--r--src/passes/Precompute.cpp18
-rw-r--r--test/example/c-api-kitchen-sink.txt40
-rw-r--r--test/example/c-api-kitchen-sink.txt.txt20
-rw-r--r--test/passes/precompute.txt33
-rw-r--r--test/passes/precompute.wast12
m---------test/spec0
-rw-r--r--test/unit.asm.js4
-rw-r--r--test/unit.fromasm12
-rw-r--r--test/unit.fromasm.imprecise12
-rw-r--r--test/unit.fromasm.imprecise.no-opts4
-rw-r--r--test/unit.fromasm.no-opts4
11 files changed, 51 insertions, 108 deletions
diff --git a/src/passes/Precompute.cpp b/src/passes/Precompute.cpp
index a341ba938..008058d58 100644
--- a/src/passes/Precompute.cpp
+++ b/src/passes/Precompute.cpp
@@ -15,23 +15,14 @@
*/
//
-// Removes dead, i.e. unreachable, code.
-//
-// We keep a record of when control flow is reachable. When it isn't, we
-// kill (turn into unreachable). We then fold away entire unreachable
-// expressions.
-//
-// When dead code causes an operation to not happen, like a store, a call
-// or an add, we replace with a block with a list of what does happen.
-// That isn't necessarily smaller, but blocks are friendlier to other
-// optimizations: blocks can be merged and eliminated, and they clearly
-// have no side effects.
+// Computes code at compile time where possible.
//
#include <wasm.h>
#include <pass.h>
#include <wasm-builder.h>
#include <wasm-interpreter.h>
+#include <ast_utils.h>
namespace wasm {
@@ -90,7 +81,7 @@ struct Precompute : public WalkerPass<PostWalker<Precompute, UnifiedExpressionVi
Pass* create() override { return new Precompute; }
void visitExpression(Expression* curr) {
- if (curr->is<Const>()) return;
+ if (curr->is<Const>() || curr->is<Nop>()) return;
// try to evaluate this into a const
Flow flow;
try {
@@ -99,8 +90,11 @@ struct Precompute : public WalkerPass<PostWalker<Precompute, UnifiedExpressionVi
return;
}
if (flow.breaking()) return; // TODO: can create a break as a replacement in some cases (not NONSTANDALONE)
+ // this was precomputed
if (isConcreteWasmType(flow.value.type)) {
replaceCurrent(Builder(*getModule()).makeConst(flow.value));
+ } else {
+ ExpressionManipulator::nop(curr);
}
}
};
diff --git a/test/example/c-api-kitchen-sink.txt b/test/example/c-api-kitchen-sink.txt
index b7b4821ac..8cc6a0a1c 100644
--- a/test/example/c-api-kitchen-sink.txt
+++ b/test/example/c-api-kitchen-sink.txt
@@ -1128,9 +1128,6 @@ optimized:
(call $check
(i32.const 1)
)
- (br_if $block$7$break
- (i32.const 0)
- )
(call $check
(i32.const 2)
)
@@ -1162,23 +1159,6 @@ optimized:
(i32.const 0)
)
(block $switch$1$leave
- (block $switch$1$default
- (block $switch$1$case$3
- (block $switch$1$case$2
- (br_table $switch$1$default $switch$1$default $switch$1$case$2 $switch$1$default $switch$1$case$3 $switch$1$case$2 $switch$1$default
- (i32.const -99)
- )
- )
- (call $check
- (i32.const 1)
- )
- (br $switch$1$leave)
- )
- (call $check
- (i32.const 2)
- )
- (br $switch$1$leave)
- )
(call $check
(i32.const 3)
)
@@ -3187,9 +3167,6 @@ optimized:
(call $check
(i32.const 1)
)
- (br_if $block$7$break
- (i32.const 0)
- )
(call $check
(i32.const 2)
)
@@ -3221,23 +3198,6 @@ optimized:
(i32.const 0)
)
(block $switch$1$leave
- (block $switch$1$default
- (block $switch$1$case$3
- (block $switch$1$case$2
- (br_table $switch$1$default $switch$1$default $switch$1$case$2 $switch$1$default $switch$1$case$3 $switch$1$case$2 $switch$1$default
- (i32.const -99)
- )
- )
- (call $check
- (i32.const 1)
- )
- (br $switch$1$leave)
- )
- (call $check
- (i32.const 2)
- )
- (br $switch$1$leave)
- )
(call $check
(i32.const 3)
)
diff --git a/test/example/c-api-kitchen-sink.txt.txt b/test/example/c-api-kitchen-sink.txt.txt
index a6f6e0853..1ce2c903a 100644
--- a/test/example/c-api-kitchen-sink.txt.txt
+++ b/test/example/c-api-kitchen-sink.txt.txt
@@ -1121,9 +1121,6 @@
(call $check
(i32.const 1)
)
- (br_if $block$7$break
- (i32.const 0)
- )
(call $check
(i32.const 2)
)
@@ -1155,23 +1152,6 @@
(i32.const 0)
)
(block $switch$1$leave
- (block $switch$1$default
- (block $switch$1$case$3
- (block $switch$1$case$2
- (br_table $switch$1$default $switch$1$default $switch$1$case$2 $switch$1$default $switch$1$case$3 $switch$1$case$2 $switch$1$default
- (i32.const -99)
- )
- )
- (call $check
- (i32.const 1)
- )
- (br $switch$1$leave)
- )
- (call $check
- (i32.const 2)
- )
- (br $switch$1$leave)
- )
(call $check
(i32.const 3)
)
diff --git a/test/passes/precompute.txt b/test/passes/precompute.txt
index 9825594b6..9c3640757 100644
--- a/test/passes/precompute.txt
+++ b/test/passes/precompute.txt
@@ -2,26 +2,35 @@
(memory 0)
(type $0 (func (param i32)))
(func $x (type $0) (param $x i32)
- (drop
- (i32.const 3)
- )
+ (nop)
(drop
(i32.add
(i32.const 1)
(get_local $x)
)
)
- (drop
- (i32.const 6)
- )
- (drop
- (i32.const -1)
- )
- (drop
- (i32.const 3)
- )
+ (nop)
+ (nop)
+ (nop)
(loop $in
(br $in)
)
+ (nop)
+ (if
+ (i32.const 2)
+ (call $x
+ (i32.const 3)
+ )
+ )
+ (nop)
+ (block $c
+ (nop)
+ (call $x
+ (i32.const 4)
+ )
+ (br_if $c
+ (i32.const 1)
+ )
+ )
)
)
diff --git a/test/passes/precompute.wast b/test/passes/precompute.wast
index 808485a34..ab7f0e3ad 100644
--- a/test/passes/precompute.wast
+++ b/test/passes/precompute.wast
@@ -41,5 +41,17 @@
(loop $in
(br $in)
)
+ (if (i32.const 0) (call $x (i32.const 1)))
+ (if (i32.const 2) (call $x (i32.const 3)))
+ (block $b
+ (br_if $b (i32.const 0))
+ (br_if $b (i32.const 1))
+ (call $x (i32.const 4))
+ )
+ (block $c
+ (br_if $c (i32.const 0))
+ (call $x (i32.const 4))
+ (br_if $c (i32.const 1))
+ )
)
)
diff --git a/test/spec b/test/spec
-Subproject 237f9ee630e951149e73d32633aa78616559519
+Subproject ef185d9cc6466f6d60c0117218f6d2144389676
diff --git a/test/unit.asm.js b/test/unit.asm.js
index 7b4b2a96f..86be4cf2f 100644
--- a/test/unit.asm.js
+++ b/test/unit.asm.js
@@ -205,7 +205,7 @@ function asm(global, env, buffer) {
print(1);
do {
print(5);
- if (0) continue;
+ if (return_int()) continue;
} while (0);
print(2);
}
@@ -275,7 +275,7 @@ function asm(global, env, buffer) {
}
function dropCall() {
- if (0) {
+ if (return_int() | 0) {
phi(); // drop this
setTempRet0(10); // this too
zeroInit(setTempRet0(10) | 0);
diff --git a/test/unit.fromasm b/test/unit.fromasm
index 123e087e6..6d0952bd4 100644
--- a/test/unit.fromasm
+++ b/test/unit.fromasm
@@ -358,7 +358,7 @@
(i32.const 5)
)
(br_if $unlikely-continue$3
- (i32.const 0)
+ (call $return_int)
)
)
(call $print
@@ -519,7 +519,7 @@
)
(func $dropCall (result i32)
(if
- (i32.const 0)
+ (call $return_int)
(block
(drop
(call $phi)
@@ -1013,13 +1013,7 @@
)
)
(func $jumpThreadDrop (result i32)
- (local $0 i32)
- (set_local $0
- (call $return_int)
- )
- (block $jumpthreading$outer$2
- )
- (get_local $0)
+ (call $return_int)
)
(func $dropIgnoredImportInIf (param $0 i32) (param $1 i32) (param $2 i32)
(if
diff --git a/test/unit.fromasm.imprecise b/test/unit.fromasm.imprecise
index b170c8b82..1e50ad731 100644
--- a/test/unit.fromasm.imprecise
+++ b/test/unit.fromasm.imprecise
@@ -339,7 +339,7 @@
(i32.const 5)
)
(br_if $unlikely-continue$3
- (i32.const 0)
+ (call $return_int)
)
)
(call $print
@@ -500,7 +500,7 @@
)
(func $dropCall (result i32)
(if
- (i32.const 0)
+ (call $return_int)
(block
(drop
(call $phi)
@@ -994,13 +994,7 @@
)
)
(func $jumpThreadDrop (result i32)
- (local $0 i32)
- (set_local $0
- (call $return_int)
- )
- (block $jumpthreading$outer$2
- )
- (get_local $0)
+ (call $return_int)
)
(func $dropIgnoredImportInIf (param $0 i32) (param $1 i32) (param $2 i32)
(if
diff --git a/test/unit.fromasm.imprecise.no-opts b/test/unit.fromasm.imprecise.no-opts
index 913920f8b..f851b86c9 100644
--- a/test/unit.fromasm.imprecise.no-opts
+++ b/test/unit.fromasm.imprecise.no-opts
@@ -591,7 +591,7 @@
(i32.const 5)
)
(if
- (i32.const 0)
+ (call $return_int)
(br $unlikely-continue$3)
)
)
@@ -870,7 +870,7 @@
)
(func $dropCall (result i32)
(if
- (i32.const 0)
+ (call $return_int)
(block
(drop
(call $phi)
diff --git a/test/unit.fromasm.no-opts b/test/unit.fromasm.no-opts
index 21e7ea79e..a7580f991 100644
--- a/test/unit.fromasm.no-opts
+++ b/test/unit.fromasm.no-opts
@@ -597,7 +597,7 @@
(i32.const 5)
)
(if
- (i32.const 0)
+ (call $return_int)
(br $unlikely-continue$3)
)
)
@@ -876,7 +876,7 @@
)
(func $dropCall (result i32)
(if
- (i32.const 0)
+ (call $return_int)
(block
(drop
(call $phi)
generated by cgit v1.2.3 (git 2.39.1) at 2025-08-06 19:13:00 +0000