Make it possible to skip several passes

src/tools/optimization-options.h

@@ -293,7 +293,7 @@ struct OptimizationOptions : public ToolOptions {
            "-sp",
            "Skip a pass (do not run it)",
            OptimizationOptionsCategory,
-           Options::Arguments::One,
+           Options::Arguments::N,
            [this](Options*, const std::string& pass) {
              passOptions.passesToSkip.insert(pass);
            });

test/lit/passes/O1_skip_passes.wast

@@ -0,0 +1,65 @@
+;; NOTE: Assertions have been generated by update_lit_checks.py and should not be edited.
+
+;; RUN: foreach %s %t wasm-opt -O2 --skip-pass=coalesce-locals --skip-pass=simplify-locals --skip-pass=simplify-locals-nostructure -S -o - 2>&1 | filecheck %s
+
+;; Check that we can skip several passes. Note that no local.tee is introduced.
+
+(module
+ ;; CHECK:      (import "a" "b" (func $log (param i32 i32)))
+ (import "a" "b" (func $log (param i32 i32)))
+
+ ;; CHECK:      (func $foo (param $p i32)
+ ;; CHECK-NEXT:  (local $x i32)
+ ;; CHECK-NEXT:  (local $y i32)
+ ;; CHECK-NEXT:  (local.set $x
+ ;; CHECK-NEXT:   (i32.add
+ ;; CHECK-NEXT:    (local.get $p)
+ ;; CHECK-NEXT:    (i32.const 1)
+ ;; CHECK-NEXT:   )
+ ;; CHECK-NEXT:  )
+ ;; CHECK-NEXT:  (call $log
+ ;; CHECK-NEXT:   (local.get $x)
+ ;; CHECK-NEXT:   (local.get $x)
+ ;; CHECK-NEXT:  )
+ ;; CHECK-NEXT:  (local.set $y
+ ;; CHECK-NEXT:   (i32.add
+ ;; CHECK-NEXT:    (local.get $p)
+ ;; CHECK-NEXT:    (i32.const 1)
+ ;; CHECK-NEXT:   )
+ ;; CHECK-NEXT:  )
+ ;; CHECK-NEXT:  (call $log
+ ;; CHECK-NEXT:   (local.get $y)
+ ;; CHECK-NEXT:   (local.get $y)
+ ;; CHECK-NEXT:  )
+ ;; CHECK-NEXT: )
+ (func $foo (export "foo") (param $p i32)
+  ;; The locals $x and $y can be coalesced into a single local, but as
+  ;; we do not run that pass, they will not be. They could be
+  ;; initialized using a tee but the passes that introduce tees are
+  ;; not run either.
+  (local $x i32)
+  (local $y i32)
+
+  (local.set $x
+   (i32.add
+    (local.get $p)
+    (i32.const 1)
+   )
+  )
+  (call $log
+   (local.get $x)
+   (local.get $x)
+  )
+
+  (local.set $y
+   (i32.add
+    (local.get $p)
+    (i32.const 1)
+   )
+  )
+  (call $log
+   (local.get $y)
+   (local.get $y)
+  )
+ )
+)