diff --git a/gen/asm-x86-32.h b/gen/asm-x86-32.h
index b2f06c77..f82ca750 100644
--- a/gen/asm-x86-32.h
+++ b/gen/asm-x86-32.h
@@ -1419,12 +1419,6 @@ namespace AsmParserx8632
                 {
                     nextToken();
                 }
-		else if ( token->value == TOKint16 || token->value == TOKint32 )
-                {
-		    //throw away the 'short' in "jle short label;". Works for 'long' also.
-		    operands[0] = operands[1];
-                    return;
-                }
                 else if ( token->value != TOKeof )
                 {
                     ok = false;
@@ -1885,11 +1879,37 @@ namespace AsmParserx8632
                     insnTemplate.write(mnemonic, mlen-1) << tc_1 << type_char;
                 }
                 break;
+                
+                case Op_FMath0:
+                // the no-operand versions of floating point ops always pop
+                insnTemplate << mnemonic << "p";
+                break;
+                
                 default:
+                // special case fdiv, fsub: see dmd 840, ldc 256
+                if (strncmp(mnemonic, "fsub", 4) == 0 ||
+                    strncmp(mnemonic, "fdiv", 4) == 0)
+                {
+                    // replace:
+                    //   f{sub,div}r{p,} <-> f{sub,div}{p,}
+                    if (mnemonic[4] == 'r')
+                    {
+                        insnTemplate.write(mnemonic, 4);
+                        insnTemplate.write(mnemonic+5, strlen(mnemonic)-5);
+                    }
+                    else
+                    {
+                        insnTemplate.write(mnemonic, 4) << "r";
+                        insnTemplate.write(mnemonic+4, strlen(mnemonic)-4);
+                    }
+                }
+                else
+                {
                     insnTemplate << mnemonic;
-                    if ( type_char )
-                        insnTemplate << type_char;
-                    break;
+                }
+                if ( type_char )
+                    insnTemplate << type_char;
+                break;
             }
 
             switch ( opInfo->implicitClobbers & Clb_DXAX_Mask )
@@ -2715,6 +2735,10 @@ namespace AsmParserx8632
             Expression * e;
             Identifier * ident = NULL;
 
+            // get rid of short/long prefixes for branches
+            if (opTakesLabel() && (token->value == TOKint16 || token->value == TOKint64))
+                nextToken();
+
             switch ( token->value )
             {
                 case TOKint32v:
@@ -2861,10 +2885,6 @@ namespace AsmParserx8632
                     ident = Id::__dollar;
                     goto do_dollar;
                     break;
-	        case TOKint16:
-	        case TOKint32:
-		    //This if for the 'short' in "jle short Label;"
-		    return Handled;
                 default:
                     if ( op == Op_FMath0 || op == Op_FdST0ST1 || op == Op_FMath )
                         return Handled;
diff --git a/gen/asm-x86-64.h b/gen/asm-x86-64.h
index 3060da0c..a895f261 100644
--- a/gen/asm-x86-64.h
+++ b/gen/asm-x86-64.h
@@ -1541,12 +1541,6 @@ namespace AsmParserx8664
                 {
                     nextToken();
                 }
-                else if ( token->value == TOKint16 || token->value == TOKint32 || token->value == TOKint64 )
-                {
-                    //throw away the 'short' in "jle short Label;". Works for long also.
-                    operands[0] = operands[1];
-                    return;
-                }
                 else if ( token->value != TOKeof )
                 {
                     ok = false;
@@ -2007,11 +2001,37 @@ namespace AsmParserx8664
                     insnTemplate.write(mnemonic, mlen-1) << tc_1 << type_char;
                 }
                 break;
+
+                case Op_FMath0:
+                // the no-operand versions of floating point ops always pop
+                insnTemplate << mnemonic << "p";
+                break;
+                
                 default:
+                // special case fdiv, fsub: see dmd 840, ldc 256
+                if (strncmp(mnemonic, "fsub", 4) == 0 ||
+                    strncmp(mnemonic, "fdiv", 4) == 0)
+                {
+                    // replace:
+                    //   f{sub,div}r{p,} <-> f{sub,div}{p,}
+                    if (mnemonic[4] == 'r')
+                    {
+                        insnTemplate.write(mnemonic, 4);
+                        insnTemplate.write(mnemonic+5, strlen(mnemonic)-5);
+                    }
+                    else
+                    {
+                        insnTemplate.write(mnemonic, 4) << "r";
+                        insnTemplate.write(mnemonic+4, strlen(mnemonic)-4);
+                    }
+                }
+                else
+                {
                     insnTemplate << mnemonic;
-                    if ( type_char )
-                        insnTemplate << type_char;
-                    break;
+                }
+                if ( type_char )
+                    insnTemplate << type_char;
+                break;
             }
 
             switch ( opInfo->implicitClobbers & Clb_DXAX_Mask )
@@ -2838,6 +2858,10 @@ namespace AsmParserx8664
             Expression * e;
             Identifier * ident = NULL;
 
+            // get rid of short/long prefixes for branches
+            if (opTakesLabel() && (token->value == TOKint16 || token->value == TOKint64))
+                nextToken();
+
             switch ( token->value )
             {
                 case TOKint32v:
@@ -2984,12 +3008,6 @@ namespace AsmParserx8664
                     ident = Id::__dollar;
                     goto do_dollar;
                     break;
-                case TOKint16:
-                case TOKint32:
-                case TOKint64:
-                    //This is for the 'short' in "jle short Label;"
-                    return Handled;
-                    break;
                 default:
                     if ( op == Op_FMath0 || op == Op_FdST0ST1 || op == Op_FMath )
                         return Handled;