diff options
| -rw-r--r-- | src/passes/SimplifyGlobals.cpp | 40 | ||||
| -rw-r--r-- | test/lit/passes/simplify-globals-offsets.wast | 85 |
2 files changed, 117 insertions, 8 deletions
diff --git a/src/passes/SimplifyGlobals.cpp b/src/passes/SimplifyGlobals.cpp index 0e66b5926..3baec4409 100644 --- a/src/passes/SimplifyGlobals.cpp +++ b/src/passes/SimplifyGlobals.cpp @@ -646,23 +646,47 @@ struct SimplifyGlobals : public Pass { // since we do know the value during startup, it can't be modified until // code runs. void propagateConstantsToGlobals() { - // Go over the list of globals in order, which is the order of - // initialization as well, tracking their constant values. + Builder builder(*module); + + // We will note constant globals here as we compute them. std::map<Name, Literals> constantGlobals; + + // Given an init expression (something like the init of a global or a + // segment), see if it is a simple global.get of a constant that we can + // apply. + auto applyGlobals = [&](Expression*& init) { + if (!init) { + // This is the init of a passive segment, which is null. + return; + } + if (auto* get = init->dynCast<GlobalGet>()) { + auto iter = constantGlobals.find(get->name); + if (iter != constantGlobals.end()) { + init = builder.makeConstantExpression(iter->second); + } + } + }; + + // Go over the list of globals first, and note their constant values as we + // go, as well as applying them where possible. for (auto& global : module->globals) { if (!global->imported()) { if (Properties::isConstantExpression(global->init)) { constantGlobals[global->name] = getLiteralsFromConstExpression(global->init); - } else if (auto* get = global->init->dynCast<GlobalGet>()) { - auto iter = constantGlobals.find(get->name); - if (iter != constantGlobals.end()) { - Builder builder(*module); - global->init = builder.makeConstantExpression(iter->second); - } + } else { + applyGlobals(global->init); } } } + + // Go over other things with inits and apply globals there. + for (auto& elementSegment : module->elementSegments) { + applyGlobals(elementSegment->offset); + } + for (auto& dataSegment : module->dataSegments) { + applyGlobals(dataSegment->offset); + } } // Constant propagation part 2: apply the values of immutable globals diff --git a/test/lit/passes/simplify-globals-offsets.wast b/test/lit/passes/simplify-globals-offsets.wast new file mode 100644 index 000000000..077c51e73 --- /dev/null +++ b/test/lit/passes/simplify-globals-offsets.wast @@ -0,0 +1,85 @@ +;; NOTE: Assertions have been generated by update_lit_checks.py --all-items and should not be edited. +;; NOTE: This test was ported using port_passes_tests_to_lit.py and could be cleaned up. + +;; RUN: foreach %s %t wasm-opt --simplify-globals -all -S -o - | filecheck %s + +;; Apply constant globals to segment offsets. The non-imported global.gets will +;; be applied in the segments named $use-defined. + +(module + ;; CHECK: (type $0 (func)) + + ;; CHECK: (import "env" "memory" (memory $memory 256)) + (import "env" "memory" (memory $memory 256)) + + ;; CHECK: (import "env" "table" (table $table 0 funcref)) + (import "env" "table" (table $table 0 funcref)) + + ;; CHECK: (import "env" "imported" (global $imported i32)) + (import "env" "imported" (global $imported i32)) + + ;; CHECK: (global $defined i32 (i32.const 42)) + (global $defined i32 (i32.const 42)) + + ;; CHECK: (global $use-defined i32 (i32.const 42)) + (global $use-defined i32 (global.get $defined)) + + ;; CHECK: (data $use-imported (global.get $imported) "hello, world!") + (data $use-imported (global.get $imported) "hello, world!") + + ;; CHECK: (data $use-defined (i32.const 42) "hello, world!") + (data $use-defined (global.get $defined) "hello, world!") + + ;; A passive segment has no offset to test, which we should not error on. + ;; CHECK: (data $dropped "hello, world!") + (data $dropped "hello, world!") + + ;; CHECK: (elem $use-imported (global.get $imported) $func) + (elem $use-imported (global.get $imported) $func) + + ;; CHECK: (elem $use-defined (i32.const 42) $func $func) + (elem $use-defined (global.get $defined) $func $func) + + ;; CHECK: (export "func" (func $func)) + (export "func" (func $func)) + + ;; CHECK: (func $func (type $0) + ;; CHECK-NEXT: (drop + ;; CHECK-NEXT: (i32.load + ;; CHECK-NEXT: (i32.const 0) + ;; CHECK-NEXT: ) + ;; CHECK-NEXT: ) + ;; CHECK-NEXT: (drop + ;; CHECK-NEXT: (table.get $table + ;; CHECK-NEXT: (i32.const 0) + ;; CHECK-NEXT: ) + ;; CHECK-NEXT: ) + ;; CHECK-NEXT: (drop + ;; CHECK-NEXT: (global.get $imported) + ;; CHECK-NEXT: ) + ;; CHECK-NEXT: (drop + ;; CHECK-NEXT: (i32.const 42) + ;; CHECK-NEXT: ) + ;; CHECK-NEXT: (data.drop $dropped) + ;; CHECK-NEXT: ) + (func $func + ;; Use things to avoid DCE. + (drop + (i32.load + (i32.const 0) + ) + ) + (drop + (table.get $table + (i32.const 0) + ) + ) + (drop + (global.get $imported) + ) + (drop + (global.get $use-defined) + ) + (data.drop $dropped) + ) +) |