New Dealign pass: reduce load/store alignment to 1 (#3010)

Pretty trivial, but will be useful in wasm2js testing, where we
can't assume an incorrectly-aligned load/store will still work,
so we'll need to be pessimistic about alignment there.

2 files changed, 44 insertions, 0 deletions

diff --git a/test/passes/dealign.txt b/test/passes/dealign.txt
new file mode 100644
index 000000000..379241da9
--- /dev/null
+++ b/test/passes/dealign.txt
@@ -0,0 +1,33 @@
+(module
+ (type $none_=>_none (func))
+ (memory $0 1 1)
+ (func $test
+  (drop
+   (i32.load align=1
+    (i32.const 4)
+   )
+  )
+  (drop
+   (i32.load align=1
+    (i32.const 8)
+   )
+  )
+  (drop
+   (i32.load align=1
+    (i32.const 12)
+   )
+  )
+  (i32.store align=1
+   (i32.const 16)
+   (i32.const 28)
+  )
+  (i32.store align=1
+   (i32.const 20)
+   (i32.const 32)
+  )
+  (i32.store align=1
+   (i32.const 24)
+   (i32.const 36)
+  )
+ )
+)
diff --git a/test/passes/dealign.wast b/test/passes/dealign.wast
new file mode 100644
index 000000000..c7116daca
--- /dev/null
+++ b/test/passes/dealign.wast
@@ -0,0 +1,11 @@
+(module
+ (memory $0 1 1)
+ (func $test
+  (drop (i32.load         (i32.const 4)))
+  (drop (i32.load align=1 (i32.const 8)))
+  (drop (i32.load align=2 (i32.const 12)))
+  (i32.store         (i32.const 16) (i32.const 28))
+  (i32.store align=1 (i32.const 20) (i32.const 32))
+  (i32.store align=2 (i32.const 24) (i32.const 36))
+ )
+)