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-rw-r--r--src/ir/linear-execution.h47
-rw-r--r--src/passes/SimplifyLocals.cpp5
-rw-r--r--test/lit/passes/Oz.wast6
-rw-r--r--test/lit/passes/inlining-optimizing_optimize-level=3.wast20
-rw-r--r--test/lit/passes/simplify-locals-eh.wast95
-rw-r--r--test/lit/passes/simplify-locals-gc.wast9
-rw-r--r--test/lit/passes/type-ssa_and_merging.wast4
-rw-r--r--test/wasm2js/i64-ctz.2asm.js1
-rw-r--r--test/wasm2js/unary-ops.2asm.js1
9 files changed, 163 insertions, 25 deletions
diff --git a/src/ir/linear-execution.h b/src/ir/linear-execution.h
index cee039b37..b7020f7fb 100644
--- a/src/ir/linear-execution.h
+++ b/src/ir/linear-execution.h
@@ -44,14 +44,49 @@ struct LinearExecutionWalker : public PostWalker<SubType, VisitorType> {
self->noteNonLinear(*currp);
}
+ // Optionally, we can connect adjacent basic blocks. "Adjacent" here means
+ // that the first branches to the second, and that there is no other code in
+ // between them. As a result, the first dominates the second, but it might not
+ // reach it.
+ //
+ // For example, a call may branch if exceptions are enabled, but if this
+ // option is flipped on then we will *not* call doNoteNonLinear on the call:
+ //
+ // ..A..
+ // call();
+ // ..B..
+ //
+ // As a result, we'd consider A and B to be together. Another example is an
+ // if:
+ //
+ // ..A..
+ // if
+ // ..B..
+ // else
+ // ..C..
+ // end
+ //
+ // Here we will connect A and B, but *not* A and C (there is code in between)
+ // or B and C (they do not branch to each other).
+ //
+ // As the if case shows, this can be useful for cases where we want to look at
+ // dominated blocks with their dominator, but it only handles the trivial
+ // adjacent cases of such dominance. Passes should generally uses a full CFG
+ // and dominator tree for this, but this option does help some very common
+ // cases (calls, if without an else) and it has very low overhead (we still
+ // only do a simple postorder walk on the IR, no CFG is constructed, etc.).
+ bool connectAdjacentBlocks = false;
+
static void scan(SubType* self, Expression** currp) {
Expression* curr = *currp;
auto handleCall = [&](bool isReturn) {
- // Control is nonlinear if we return, or if EH is enabled or may be.
- if (isReturn || !self->getModule() ||
- self->getModule()->features.hasExceptionHandling()) {
- self->pushTask(SubType::doNoteNonLinear, currp);
+ if (!self->connectAdjacentBlocks) {
+ // Control is nonlinear if we return, or if EH is enabled or may be.
+ if (isReturn || !self->getModule() ||
+ self->getModule()->features.hasExceptionHandling()) {
+ self->pushTask(SubType::doNoteNonLinear, currp);
+ }
}
// Scan the children normally.
@@ -78,7 +113,9 @@ struct LinearExecutionWalker : public PostWalker<SubType, VisitorType> {
self->maybePushTask(SubType::scan, &curr->cast<If>()->ifFalse);
self->pushTask(SubType::doNoteNonLinear, currp);
self->pushTask(SubType::scan, &curr->cast<If>()->ifTrue);
- self->pushTask(SubType::doNoteNonLinear, currp);
+ if (!self->connectAdjacentBlocks) {
+ self->pushTask(SubType::doNoteNonLinear, currp);
+ }
self->pushTask(SubType::scan, &curr->cast<If>()->condition);
break;
}
diff --git a/src/passes/SimplifyLocals.cpp b/src/passes/SimplifyLocals.cpp
index ff2141fb4..fb46c79ec 100644
--- a/src/passes/SimplifyLocals.cpp
+++ b/src/passes/SimplifyLocals.cpp
@@ -998,6 +998,11 @@ struct SimplifyLocals
struct EquivalentOptimizer
: public LinearExecutionWalker<EquivalentOptimizer> {
+ // It is ok to look at adjacent blocks together, as if a later part of a
+ // block is not reached that is fine - changes we make there would not be
+ // reached in that case.
+ bool connectAdjacentBlocks = true;
+
std::vector<Index>* numLocalGets;
bool removeEquivalentSets;
PassOptions passOptions;
diff --git a/test/lit/passes/Oz.wast b/test/lit/passes/Oz.wast
index 56b27c047..3a6ac1f7d 100644
--- a/test/lit/passes/Oz.wast
+++ b/test/lit/passes/Oz.wast
@@ -195,11 +195,9 @@
)
;; CHECK: (func $12 (type $i32_i32_=>_i32) (; has Stack IR ;) (param $0 i32) (param $1 i32) (result i32)
;; CHECK-NEXT: (if
- ;; CHECK-NEXT: (local.tee $1
- ;; CHECK-NEXT: (local.get $0)
- ;; CHECK-NEXT: )
+ ;; CHECK-NEXT: (local.get $0)
;; CHECK-NEXT: (return
- ;; CHECK-NEXT: (local.get $1)
+ ;; CHECK-NEXT: (local.get $0)
;; CHECK-NEXT: )
;; CHECK-NEXT: )
;; CHECK-NEXT: (i32.const 0)
diff --git a/test/lit/passes/inlining-optimizing_optimize-level=3.wast b/test/lit/passes/inlining-optimizing_optimize-level=3.wast
index 29ee11b46..c6c4f389c 100644
--- a/test/lit/passes/inlining-optimizing_optimize-level=3.wast
+++ b/test/lit/passes/inlining-optimizing_optimize-level=3.wast
@@ -6818,7 +6818,7 @@
;; CHECK-NEXT: (i32.mul
;; CHECK-NEXT: (i32.shr_s
;; CHECK-NEXT: (i32.sub
- ;; CHECK-NEXT: (local.get $20)
+ ;; CHECK-NEXT: (local.get $8)
;; CHECK-NEXT: (local.get $5)
;; CHECK-NEXT: )
;; CHECK-NEXT: (i32.const 2)
@@ -8423,9 +8423,7 @@
;; CHECK-NEXT: (i32.and
;; CHECK-NEXT: (local.tee $9
;; CHECK-NEXT: (i32.ne
- ;; CHECK-NEXT: (local.tee $7
- ;; CHECK-NEXT: (local.get $6)
- ;; CHECK-NEXT: )
+ ;; CHECK-NEXT: (local.get $6)
;; CHECK-NEXT: (i32.const 0)
;; CHECK-NEXT: )
;; CHECK-NEXT: )
@@ -8438,6 +8436,9 @@
;; CHECK-NEXT: )
;; CHECK-NEXT: )
;; CHECK-NEXT: (block
+ ;; CHECK-NEXT: (local.set $7
+ ;; CHECK-NEXT: (local.get $6)
+ ;; CHECK-NEXT: )
;; CHECK-NEXT: (local.set $8
;; CHECK-NEXT: (local.get $5)
;; CHECK-NEXT: )
@@ -8478,8 +8479,13 @@
;; CHECK-NEXT: )
;; CHECK-NEXT: )
;; CHECK-NEXT: )
- ;; CHECK-NEXT: (local.set $8
- ;; CHECK-NEXT: (local.get $5)
+ ;; CHECK-NEXT: (block
+ ;; CHECK-NEXT: (local.set $7
+ ;; CHECK-NEXT: (local.get $6)
+ ;; CHECK-NEXT: )
+ ;; CHECK-NEXT: (local.set $8
+ ;; CHECK-NEXT: (local.get $5)
+ ;; CHECK-NEXT: )
;; CHECK-NEXT: )
;; CHECK-NEXT: )
;; CHECK-NEXT: (br_if $__rjti$20
@@ -8502,7 +8508,7 @@
;; CHECK-NEXT: (block $__rjti$07
;; CHECK-NEXT: (br_if $__rjti$07
;; CHECK-NEXT: (i32.le_u
- ;; CHECK-NEXT: (local.get $9)
+ ;; CHECK-NEXT: (local.get $7)
;; CHECK-NEXT: (i32.const 3)
;; CHECK-NEXT: )
;; CHECK-NEXT: )
diff --git a/test/lit/passes/simplify-locals-eh.wast b/test/lit/passes/simplify-locals-eh.wast
index 38b9d1af7..3b00857b6 100644
--- a/test/lit/passes/simplify-locals-eh.wast
+++ b/test/lit/passes/simplify-locals-eh.wast
@@ -151,4 +151,99 @@
)
)
)
+
+ ;; CHECK: (func $equivalent-set-removal-call (type $i32_=>_none) (param $0 i32)
+ ;; CHECK-NEXT: (local $1 i32)
+ ;; CHECK-NEXT: (nop)
+ ;; CHECK-NEXT: (drop
+ ;; CHECK-NEXT: (local.get $0)
+ ;; CHECK-NEXT: )
+ ;; CHECK-NEXT: (nop)
+ ;; CHECK-NEXT: (call $equivalent-set-removal-call
+ ;; CHECK-NEXT: (i32.const 2)
+ ;; CHECK-NEXT: )
+ ;; CHECK-NEXT: (drop
+ ;; CHECK-NEXT: (local.get $0)
+ ;; CHECK-NEXT: )
+ ;; CHECK-NEXT: (drop
+ ;; CHECK-NEXT: (local.get $0)
+ ;; CHECK-NEXT: )
+ ;; CHECK-NEXT: )
+ (func $equivalent-set-removal-call (param $0 i32)
+ (local $1 i32)
+ (local.set $1 (local.get $0))
+ (drop (local.get $0))
+ (drop (local.get $1))
+ ;; Even with EH enabled we can look past the call and optimize the final 1
+ ;; to a 0, since they contain the same (and while the call might branch,
+ ;; such a branch does not cause a problem here, as if we branch we just
+ ;; don't reach the change later down).
+ (call $equivalent-set-removal-call
+ (i32.const 2)
+ )
+ (drop (local.get $0))
+ (drop (local.get $1))
+ )
+
+ ;; CHECK: (func $equivalent-set-removal-if (type $i32_i32_=>_none) (param $p i32) (param $0 i32)
+ ;; CHECK-NEXT: (local $1 i32)
+ ;; CHECK-NEXT: (nop)
+ ;; CHECK-NEXT: (drop
+ ;; CHECK-NEXT: (local.get $0)
+ ;; CHECK-NEXT: )
+ ;; CHECK-NEXT: (local.set $1
+ ;; CHECK-NEXT: (local.get $0)
+ ;; CHECK-NEXT: )
+ ;; CHECK-NEXT: (if
+ ;; CHECK-NEXT: (local.get $p)
+ ;; CHECK-NEXT: (block
+ ;; CHECK-NEXT: (drop
+ ;; CHECK-NEXT: (local.get $0)
+ ;; CHECK-NEXT: )
+ ;; CHECK-NEXT: (drop
+ ;; CHECK-NEXT: (local.get $0)
+ ;; CHECK-NEXT: )
+ ;; CHECK-NEXT: )
+ ;; CHECK-NEXT: (block
+ ;; CHECK-NEXT: (drop
+ ;; CHECK-NEXT: (local.get $0)
+ ;; CHECK-NEXT: )
+ ;; CHECK-NEXT: (drop
+ ;; CHECK-NEXT: (local.get $1)
+ ;; CHECK-NEXT: )
+ ;; CHECK-NEXT: )
+ ;; CHECK-NEXT: )
+ ;; CHECK-NEXT: (drop
+ ;; CHECK-NEXT: (local.get $0)
+ ;; CHECK-NEXT: )
+ ;; CHECK-NEXT: (drop
+ ;; CHECK-NEXT: (local.get $1)
+ ;; CHECK-NEXT: )
+ ;; CHECK-NEXT: )
+ (func $equivalent-set-removal-if (param $p i32) (param $0 i32)
+ (local $1 i32)
+ (local.set $1 (local.get $0))
+ (drop (local.get $0))
+ ;; This local.get of 1 can be of 0.
+ (drop (local.get $1))
+ (if
+ (local.get $p)
+ (block
+ ;; We also optimize in this block, which is adjacent to the code before
+ ;; us. It is valid to optimize the 1 to a 0 here, as it is dominated by
+ ;; the code earlier.
+ (drop (local.get $0))
+ (drop (local.get $1))
+ )
+ (block
+ ;; We could also optimize here, but atm just look at code adjacent to
+ ;; its dominator. TODO
+ (drop (local.get $0))
+ (drop (local.get $1))
+ )
+ )
+ ;; As in the else, this could be optimized. TODO
+ (drop (local.get $0))
+ (drop (local.get $1))
+ )
)
diff --git a/test/lit/passes/simplify-locals-gc.wast b/test/lit/passes/simplify-locals-gc.wast
index 500d12b5a..6b2b10462 100644
--- a/test/lit/passes/simplify-locals-gc.wast
+++ b/test/lit/passes/simplify-locals-gc.wast
@@ -366,9 +366,7 @@
;; CHECK-NEXT: (local.get $nn-any)
;; CHECK-NEXT: )
;; CHECK-NEXT: (nop)
- ;; CHECK-NEXT: (local.tee $any
- ;; CHECK-NEXT: (local.get $nn-any)
- ;; CHECK-NEXT: )
+ ;; CHECK-NEXT: (local.get $nn-any)
;; CHECK-NEXT: )
(func $pick-casted (param $any anyref) (result anyref)
(local $nn-any (ref any))
@@ -384,10 +382,7 @@
(call $use-nn-any
(local.get $nn-any)
)
- ;; This copy is not needed, as they hold the same value. However, the call
- ;; before us inhibits us from optimizing here. TODO: with a more precise
- ;; analysis we could optimize this, as if the call branches out it doesn't
- ;; matter what happens after it.
+ ;; This copy is not needed, as they hold the same value.
(local.set $any
(local.get $nn-any)
)
diff --git a/test/lit/passes/type-ssa_and_merging.wast b/test/lit/passes/type-ssa_and_merging.wast
index 19c6bf882..9bab2bc27 100644
--- a/test/lit/passes/type-ssa_and_merging.wast
+++ b/test/lit/passes/type-ssa_and_merging.wast
@@ -22,6 +22,10 @@
;; NOP: (type $none_=>_i32 (func (result i32)))
;; NOP: (import "a" "b" (func $import (type $none_=>_i32) (result i32)))
+ ;; YES: (type $A$2 (sub $A (struct )))
+
+ ;; YES: (type $A$1 (sub $A (struct )))
+
;; YES: (import "a" "b" (func $import (type $none_=>_i32) (result i32)))
(import "a" "b" (func $import (result i32)))
diff --git a/test/wasm2js/i64-ctz.2asm.js b/test/wasm2js/i64-ctz.2asm.js
index e12cea00b..5bd8cfc9b 100644
--- a/test/wasm2js/i64-ctz.2asm.js
+++ b/test/wasm2js/i64-ctz.2asm.js
@@ -132,7 +132,6 @@ function asmFunc(imports) {
var i64toi32_i32$0 = 0, i64toi32_i32$3 = 0, i64toi32_i32$5 = 0, i64toi32_i32$4 = 0, i64toi32_i32$2 = 0, i64toi32_i32$1 = 0, $10 = 0, $5$hi = 0, $8$hi = 0;
i64toi32_i32$0 = var$0$hi;
if (!!(var$0 | i64toi32_i32$0 | 0)) {
- i64toi32_i32$0 = var$0$hi;
i64toi32_i32$2 = var$0;
i64toi32_i32$1 = -1;
i64toi32_i32$3 = -1;
diff --git a/test/wasm2js/unary-ops.2asm.js b/test/wasm2js/unary-ops.2asm.js
index 154118048..90b030e45 100644
--- a/test/wasm2js/unary-ops.2asm.js
+++ b/test/wasm2js/unary-ops.2asm.js
@@ -391,7 +391,6 @@ function asmFunc(imports) {
var i64toi32_i32$0 = 0, i64toi32_i32$3 = 0, i64toi32_i32$5 = 0, i64toi32_i32$4 = 0, i64toi32_i32$2 = 0, i64toi32_i32$1 = 0, $10 = 0, $5$hi = 0, $8$hi = 0;
i64toi32_i32$0 = var$0$hi;
if (!!(var$0 | i64toi32_i32$0 | 0)) {
- i64toi32_i32$0 = var$0$hi;
i64toi32_i32$2 = var$0;
i64toi32_i32$1 = -1;
i64toi32_i32$3 = -1;