From febb07b8b2536ba4ecef03ec54f4f2b87f113f3a Mon Sep 17 00:00:00 2001
From: Chad Retz <chad.retz@gmail.com>
Date: Sun, 23 Apr 2017 03:35:03 -0500
Subject: [PATCH] Stopped the extra pop on get/set global. Fixes #2.

---
 .../kotlin/asmble/compile/jvm/InsnReworker.kt |  5 ++--
 .../resources/local-spec/multi-global.wast    | 23 +++++++++++++++++++
 2 files changed, 25 insertions(+), 3 deletions(-)
 create mode 100644 src/test/resources/local-spec/multi-global.wast

diff --git a/src/main/kotlin/asmble/compile/jvm/InsnReworker.kt b/src/main/kotlin/asmble/compile/jvm/InsnReworker.kt
index f80a6d2..03a1d95 100644
--- a/src/main/kotlin/asmble/compile/jvm/InsnReworker.kt
+++ b/src/main/kotlin/asmble/compile/jvm/InsnReworker.kt
@@ -196,8 +196,8 @@ open class InsnReworker {
         is Node.Instr.GetLocal -> PUSH_RESULT
         is Node.Instr.SetLocal -> POP_PARAM
         is Node.Instr.TeeLocal -> POP_PARAM + PUSH_RESULT
-        is Node.Instr.GetGlobal -> POP_THIS + PUSH_RESULT
-        is Node.Instr.SetGlobal -> POP_THIS + POP_PARAM
+        is Node.Instr.GetGlobal -> PUSH_RESULT
+        is Node.Instr.SetGlobal -> POP_PARAM
         is Node.Instr.I32Load, is Node.Instr.I64Load, is Node.Instr.F32Load, is Node.Instr.F64Load,
         is Node.Instr.I32Load8S, is Node.Instr.I32Load8U, is Node.Instr.I32Load16U, is Node.Instr.I32Load16S,
         is Node.Instr.I64Load8S, is Node.Instr.I64Load8U, is Node.Instr.I64Load16U, is Node.Instr.I64Load16S,
@@ -266,7 +266,6 @@ open class InsnReworker {
     }.let { (count, _) -> count }
 
     companion object : InsnReworker() {
-        const val POP_THIS = -1
         const val POP_PARAM = -1
         const val PUSH_RESULT = 1
         const val NOP = 0
diff --git a/src/test/resources/local-spec/multi-global.wast b/src/test/resources/local-spec/multi-global.wast
new file mode 100644
index 0000000..8631f08
--- /dev/null
+++ b/src/test/resources/local-spec/multi-global.wast
@@ -0,0 +1,23 @@
+;; This was breaking because stack diff was wrong for get_global and set_global
+
+(module
+  (global $foo (mut i32) (i32.const 20))
+  (func (export "test") (param $p i32) (result i32)
+    (local i32)
+    (get_global $foo)
+    (set_local 1)
+    (get_global $foo)
+    (get_local $p)
+    (i32.add)
+    (set_global $foo)
+    (get_global $foo)
+    (i32.const 15)
+    (i32.add)
+    (i32.const -16)
+    (i32.and)
+    (set_global $foo)
+    (get_global $foo)
+  )
+)
+
+(assert_return (invoke "test" (i32.const 7)) (i32.const 32))
\ No newline at end of file