From c2be64a5259b237dad0b642ee214fc6f566a1c82 Mon Sep 17 00:00:00 2001
From: Volker Berlin <volker.berlin@googlemail.com>
Date: Tue, 12 Mar 2019 21:27:23 +0100
Subject: [PATCH] implements java bytecode frem and drem

---
 .../module/JavaMethodWasmCodeBuilder.java            |  8 ++++++--
 .../jwebassembly/module/SyntheticFunctionName.java   |  2 +-
 .../jwebassembly/runtime/MathOperations.java         |  2 ++
 .../jwebassembly/runtime/RuntimeErrors.java          | 12 ------------
 4 files changed, 9 insertions(+), 15 deletions(-)

diff --git a/src/de/inetsoftware/jwebassembly/module/JavaMethodWasmCodeBuilder.java b/src/de/inetsoftware/jwebassembly/module/JavaMethodWasmCodeBuilder.java
index 157f8b7..53af49c 100644
--- a/src/de/inetsoftware/jwebassembly/module/JavaMethodWasmCodeBuilder.java
+++ b/src/de/inetsoftware/jwebassembly/module/JavaMethodWasmCodeBuilder.java
@@ -342,9 +342,13 @@ class JavaMethodWasmCodeBuilder extends WasmCodeBuilder {
                         addNumericInstruction( NumericOperator.rem, ValueType.i64, codePos );
                         break;
                     case 114: // frem
+                        //helper function like: (a - (int)(a / b) * (float)b) 
+                        addCallInstruction( new SyntheticFunctionName( "frem", "local.get 0 local.get 0 local.get 1 f32.div i32.trunc_sat_f32_s f32.convert_i32_s local.get 1 f32.mul f32.sub return", ValueType.f32, ValueType.f32, null, ValueType.f32 ), codePos );
+                        break;
                     case 115: // drem
-                        //TODO can be implemented with a helper function like: (a - (long)(a / b) * (double)b) 
-                        throw new WasmException( "Modulo/Remainder for floating numbers is not supported in WASM. Use int or long data types." + op, byteCode.getLineNumber() );
+                        //helper function like: (a - (long)(a / b) * (double)b) 
+                        addCallInstruction( new SyntheticFunctionName( "drem", "local.get 0 local.get 0 local.get 1 f64.div i64.trunc_sat_f64_s f64.convert_i64_s local.get 1 f64.mul f64.sub return", ValueType.f64, ValueType.f64, null, ValueType.f64 ), codePos );
+                        break;
                     case 116: // ineg
                         addConstInstruction( -1, ValueType.i32, codePos );
                         addNumericInstruction( NumericOperator.mul, ValueType.i32, codePos );
diff --git a/src/de/inetsoftware/jwebassembly/module/SyntheticFunctionName.java b/src/de/inetsoftware/jwebassembly/module/SyntheticFunctionName.java
index 497430b..19f2988 100644
--- a/src/de/inetsoftware/jwebassembly/module/SyntheticFunctionName.java
+++ b/src/de/inetsoftware/jwebassembly/module/SyntheticFunctionName.java
@@ -40,7 +40,7 @@ public class SyntheticFunctionName extends FunctionName {
      * @param code
      *            the WAT code (WASM in text form)
      * @param signature
-     *            the method signature
+     *            the method signature, first the parameters, then null and the the return types
      */
     public SyntheticFunctionName( String name, String code, AnyType... signature ) {
         super( "", name, "()V" ); //TODO better signature name
diff --git a/test/de/inetsoftware/jwebassembly/runtime/MathOperations.java b/test/de/inetsoftware/jwebassembly/runtime/MathOperations.java
index f1dca73..e14c24a 100644
--- a/test/de/inetsoftware/jwebassembly/runtime/MathOperations.java
+++ b/test/de/inetsoftware/jwebassembly/runtime/MathOperations.java
@@ -181,6 +181,7 @@ public class MathOperations extends AbstractBaseTest {
             float a = -54321F;
             a *= 3F;
             a /= -8F;
+            a %= 37.5F;
             return a;
         }
 
@@ -189,6 +190,7 @@ public class MathOperations extends AbstractBaseTest {
             double a = -54321.0;
             a *= 3F;
             a /= -5F;
+            a %= 37.5;
             return a;
         }
 
diff --git a/test/de/inetsoftware/jwebassembly/runtime/RuntimeErrors.java b/test/de/inetsoftware/jwebassembly/runtime/RuntimeErrors.java
index d0ef899..0df5b6f 100644
--- a/test/de/inetsoftware/jwebassembly/runtime/RuntimeErrors.java
+++ b/test/de/inetsoftware/jwebassembly/runtime/RuntimeErrors.java
@@ -85,18 +85,6 @@ public class RuntimeErrors {
         }
 
     }
-    @Test
-    public void floatRem() throws IOException {
-        compileErrorTest( "Modulo/Remainder", TestModulo.class );
-    }
-
-    static class TestModulo {
-        @Export
-        static float longReturn() {
-            float a = 3.4F;
-            return a % 2F;
-        }
-    }
 
     @Test
     public void nonStaticExport() throws IOException {