optimize out i32.and of -1

6 files changed, 106 insertions, 149 deletions

diff --git a/src/passes/OptimizeInstructions.cpp b/src/passes/OptimizeInstructions.cpp
index 7547f332a..0b54f9756 100644
--- a/src/passes/OptimizeInstructions.cpp
+++ b/src/passes/OptimizeInstructions.cpp
@@ -224,10 +224,15 @@ struct OptimizeInstructions : public WalkerPass<PostWalker<OptimizeInstructions,
           }
         }
       } else if (binary->op == AndInt32) {
-        if (auto* load = binary->left->dynCast<Load>()) {
-          if (auto* right = binary->right->dynCast<Const>()) {
-            if (right->type == i32) {
-              auto mask = right->value.geti32();
+        if (auto* right = binary->right->dynCast<Const>()) {
+          if (right->type == i32) {
+            auto mask = right->value.geti32();
+            // and with -1 does nothing (common in asm.js output)
+            if (mask == -1) {
+              return binary->left;
+            }
+            // small loads do not need to be masted, the load itself masks
+            if (auto* load = binary->left->dynCast<Load>()) {
               if ((load->bytes == 1 && mask == 0xff) ||
                   (load->bytes == 2 && mask == 0xffff)) {
                 load->signed_ = false;
diff --git a/test/emcc_hello_world.fromasm b/test/emcc_hello_world.fromasm
index e5f68f021..c6815b60d 100644
--- a/test/emcc_hello_world.fromasm
+++ b/test/emcc_hello_world.fromasm
@@ -4930,15 +4930,12 @@
                                       (block
                                         (set_local $12
                                           (i32.add
-                                            (i32.and
-                                              (call $i32s-div
-                                                (i32.add
-                                                  (get_local $19)
-                                                  (i32.const 25)
-                                                )
-                                                (i32.const 9)
+                                            (call $i32s-div
+                                              (i32.add
+                                                (get_local $19)
+                                                (i32.const 25)
                                               )
-                                              (i32.const -1)
+                                              (i32.const 9)
                                             )
                                             (i32.const 1)
                                           )
@@ -5246,17 +5243,14 @@
                                               )
                                               (i32.shl
                                                 (i32.add
-                                                  (i32.and
-                                                    (call $i32s-div
-                                                      (tee_local $11
-                                                        (i32.add
-                                                          (get_local $7)
-                                                          (i32.const 9216)
-                                                        )
+                                                  (call $i32s-div
+                                                    (tee_local $11
+                                                      (i32.add
+                                                        (get_local $7)
+                                                        (i32.const 9216)
                                                       )
-                                                      (i32.const 9)
                                                     )
-                                                    (i32.const -1)
+                                                    (i32.const 9)
                                                   )
                                                   (i32.const -1024)
                                                 )
@@ -5268,12 +5262,9 @@
                                             (i32.lt_s
                                               (tee_local $11
                                                 (i32.add
-                                                  (i32.and
-                                                    (call $i32s-rem
-                                                      (get_local $11)
-                                                      (i32.const 9)
-                                                    )
-                                                    (i32.const -1)
+                                                  (call $i32s-rem
+                                                    (get_local $11)
+                                                    (i32.const 9)
                                                   )
                                                   (i32.const 1)
                                                 )
@@ -5323,16 +5314,13 @@
                                                   )
                                                   (i32.eqz
                                                     (tee_local $31
-                                                      (i32.and
-                                                        (call $i32u-rem
-                                                          (tee_local $11
-                                                            (i32.load
-                                                              (get_local $7)
-                                                            )
+                                                      (call $i32u-rem
+                                                        (tee_local $11
+                                                          (i32.load
+                                                            (get_local $7)
                                                           )
-                                                          (get_local $12)
                                                         )
-                                                        (i32.const -1)
+                                                        (get_local $12)
                                                       )
                                                     )
                                                   )
@@ -5344,12 +5332,9 @@
                                                     (f64.const 9007199254740994)
                                                     (f64.const 9007199254740992)
                                                     (i32.and
-                                                      (i32.and
-                                                        (call $i32u-div
-                                                          (get_local $11)
-                                                          (get_local $12)
-                                                        )
-                                                        (i32.const -1)
+                                                      (call $i32u-div
+                                                        (get_local $11)
+                                                        (get_local $12)
                                                       )
                                                       (i32.const 1)
                                                     )
@@ -5360,12 +5345,9 @@
                                                     (i32.lt_u
                                                       (get_local $31)
                                                       (tee_local $25
-                                                        (i32.and
-                                                          (call $i32s-div
-                                                            (get_local $12)
-                                                            (i32.const 2)
-                                                          )
-                                                          (i32.const -1)
+                                                        (call $i32s-div
+                                                          (get_local $12)
+                                                          (i32.const 2)
                                                         )
                                                       )
                                                     )
@@ -5717,12 +5699,9 @@
                                                     )
                                                   )
                                                   (if
-                                                    (i32.and
-                                                      (call $i32u-rem
-                                                        (get_local $19)
-                                                        (i32.const 10)
-                                                      )
-                                                      (i32.const -1)
+                                                    (call $i32u-rem
+                                                      (get_local $19)
+                                                      (i32.const 10)
                                                     )
                                                     (block
                                                       (set_local $5
@@ -5748,17 +5727,14 @@
                                                     )
                                                     (br_if $while-in96
                                                       (i32.eqz
-                                                        (i32.and
-                                                          (call $i32u-rem
-                                                            (get_local $19)
-                                                            (tee_local $7
-                                                              (i32.mul
-                                                                (get_local $7)
-                                                                (i32.const 10)
-                                                              )
+                                                        (call $i32u-rem
+                                                          (get_local $19)
+                                                          (tee_local $7
+                                                            (i32.mul
+                                                              (get_local $7)
+                                                              (i32.const 10)
                                                             )
                                                           )
-                                                          (i32.const -1)
                                                         )
                                                       )
                                                     )
@@ -7883,23 +7859,17 @@
             )
           )
           (i32.or
-            (i32.and
-              (call $i32u-rem
-                (get_local $0)
-                (i32.const 10)
-              )
-              (i32.const -1)
+            (call $i32u-rem
+              (get_local $0)
+              (i32.const 10)
             )
             (i32.const 48)
           )
         )
         (set_local $2
-          (i32.and
-            (call $i32u-div
-              (get_local $0)
-              (i32.const 10)
-            )
-            (i32.const -1)
+          (call $i32u-div
+            (get_local $0)
+            (i32.const 10)
           )
         )
         (if
diff --git a/test/emcc_hello_world.fromasm.imprecise b/test/emcc_hello_world.fromasm.imprecise
index 589114f82..a16e45353 100644
--- a/test/emcc_hello_world.fromasm.imprecise
+++ b/test/emcc_hello_world.fromasm.imprecise
@@ -4923,15 +4923,12 @@
                                       (block
                                         (set_local $12
                                           (i32.add
-                                            (i32.and
-                                              (i32.div_s
-                                                (i32.add
-                                                  (get_local $19)
-                                                  (i32.const 25)
-                                                )
-                                                (i32.const 9)
+                                            (i32.div_s
+                                              (i32.add
+                                                (get_local $19)
+                                                (i32.const 25)
                                               )
-                                              (i32.const -1)
+                                              (i32.const 9)
                                             )
                                             (i32.const 1)
                                           )
@@ -5239,17 +5236,14 @@
                                               )
                                               (i32.shl
                                                 (i32.add
-                                                  (i32.and
-                                                    (i32.div_s
-                                                      (tee_local $11
-                                                        (i32.add
-                                                          (get_local $7)
-                                                          (i32.const 9216)
-                                                        )
+                                                  (i32.div_s
+                                                    (tee_local $11
+                                                      (i32.add
+                                                        (get_local $7)
+                                                        (i32.const 9216)
                                                       )
-                                                      (i32.const 9)
                                                     )
-                                                    (i32.const -1)
+                                                    (i32.const 9)
                                                   )
                                                   (i32.const -1024)
                                                 )
@@ -5261,12 +5255,9 @@
                                             (i32.lt_s
                                               (tee_local $11
                                                 (i32.add
-                                                  (i32.and
-                                                    (i32.rem_s
-                                                      (get_local $11)
-                                                      (i32.const 9)
-                                                    )
-                                                    (i32.const -1)
+                                                  (i32.rem_s
+                                                    (get_local $11)
+                                                    (i32.const 9)
                                                   )
                                                   (i32.const 1)
                                                 )
@@ -5316,16 +5307,13 @@
                                                   )
                                                   (i32.eqz
                                                     (tee_local $31
-                                                      (i32.and
-                                                        (i32.rem_u
-                                                          (tee_local $11
-                                                            (i32.load
-                                                              (get_local $7)
-                                                            )
+                                                      (i32.rem_u
+                                                        (tee_local $11
+                                                          (i32.load
+                                                            (get_local $7)
                                                           )
-                                                          (get_local $12)
                                                         )
-                                                        (i32.const -1)
+                                                        (get_local $12)
                                                       )
                                                     )
                                                   )
@@ -5337,12 +5325,9 @@
                                                     (f64.const 9007199254740994)
                                                     (f64.const 9007199254740992)
                                                     (i32.and
-                                                      (i32.and
-                                                        (i32.div_u
-                                                          (get_local $11)
-                                                          (get_local $12)
-                                                        )
-                                                        (i32.const -1)
+                                                      (i32.div_u
+                                                        (get_local $11)
+                                                        (get_local $12)
                                                       )
                                                       (i32.const 1)
                                                     )
@@ -5353,12 +5338,9 @@
                                                     (i32.lt_u
                                                       (get_local $31)
                                                       (tee_local $25
-                                                        (i32.and
-                                                          (i32.div_s
-                                                            (get_local $12)
-                                                            (i32.const 2)
-                                                          )
-                                                          (i32.const -1)
+                                                        (i32.div_s
+                                                          (get_local $12)
+                                                          (i32.const 2)
                                                         )
                                                       )
                                                     )
@@ -5710,12 +5692,9 @@
                                                     )
                                                   )
                                                   (if
-                                                    (i32.and
-                                                      (i32.rem_u
-                                                        (get_local $19)
-                                                        (i32.const 10)
-                                                      )
-                                                      (i32.const -1)
+                                                    (i32.rem_u
+                                                      (get_local $19)
+                                                      (i32.const 10)
                                                     )
                                                     (block
                                                       (set_local $5
@@ -5741,17 +5720,14 @@
                                                     )
                                                     (br_if $while-in96
                                                       (i32.eqz
-                                                        (i32.and
-                                                          (i32.rem_u
-                                                            (get_local $19)
-                                                            (tee_local $7
-                                                              (i32.mul
-                                                                (get_local $7)
-                                                                (i32.const 10)
-                                                              )
+                                                        (i32.rem_u
+                                                          (get_local $19)
+                                                          (tee_local $7
+                                                            (i32.mul
+                                                              (get_local $7)
+                                                              (i32.const 10)
                                                             )
                                                           )
-                                                          (i32.const -1)
                                                         )
                                                       )
                                                     )
@@ -7876,23 +7852,17 @@
             )
           )
           (i32.or
-            (i32.and
-              (i32.rem_u
-                (get_local $0)
-                (i32.const 10)
-              )
-              (i32.const -1)
+            (i32.rem_u
+              (get_local $0)
+              (i32.const 10)
             )
             (i32.const 48)
           )
         )
         (set_local $2
-          (i32.and
-            (i32.div_u
-              (get_local $0)
-              (i32.const 10)
-            )
-            (i32.const -1)
+          (i32.div_u
+            (get_local $0)
+            (i32.const 10)
           )
         )
         (if
diff --git a/test/passes/optimize-instructions.txt b/test/passes/optimize-instructions.txt
index 07cc7e895..73076b0c5 100644
--- a/test/passes/optimize-instructions.txt
+++ b/test/passes/optimize-instructions.txt
@@ -290,4 +290,15 @@
       )
     )
   )
+  (func $and-neg1 (type $1)
+    (drop
+      (i32.const 100)
+    )
+    (drop
+      (i32.and
+        (i32.const 100)
+        (i32.const 1)
+      )
+    )
+  )
 )
diff --git a/test/passes/optimize-instructions.wast b/test/passes/optimize-instructions.wast
index 939b07ffc..9701941c7 100644
--- a/test/passes/optimize-instructions.wast
+++ b/test/passes/optimize-instructions.wast
@@ -267,4 +267,8 @@
     (i32.store16 (i32.const 10) (i32.and (i32.const -3) (i32.const 65535)))
     (i32.store16 (i32.const 11) (i32.and (i32.const -4) (i32.const 65534)))
   )
+  (func $and-neg1
+    (drop (i32.and (i32.const 100) (i32.const -1)))
+    (drop (i32.and (i32.const 100) (i32.const  1)))
+  )
 )
diff --git a/test/unit.fromasm b/test/unit.fromasm
index 28bd8f223..905d12b86 100644
--- a/test/unit.fromasm
+++ b/test/unit.fromasm
@@ -254,12 +254,9 @@
     )
   )
   (func $big_uint_div_u (result i32)
-    (i32.and
-      (call $i32u-div
-        (i32.const -1)
-        (i32.const 2)
-      )
+    (call $i32u-div
       (i32.const -1)
+      (i32.const 2)
     )
   )
   (func $fr (param $0 f32)