From e4ab5974fa36ea2d32d3713b07aea1620549c8db Mon Sep 17 00:00:00 2001
From: belliash <belliash@codingworkshop.eu.org>
Date: Tue, 7 Aug 2018 07:47:25 +0200
Subject: [PATCH] Let the compiler use OP_ADD instead of OP_CAT

---
 engine/compiler.c |  2 +-
 engine/vm.c       | 11 ++++++++---
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/engine/compiler.c b/engine/compiler.c
index da88418..cf63200 100644
--- a/engine/compiler.c
+++ b/engine/compiler.c
@@ -778,7 +778,7 @@ static sxi32 GenStateCompileString(ph7_gen_state *pGen) {
 	}/*for(;;)*/
 	if(iCons > 1) {
 		/* Concatenate all compiled constants */
-		PH7_VmEmitInstr(pGen->pVm, PH7_OP_CAT, iCons, 0, 0, 0);
+		PH7_VmEmitInstr(pGen->pVm, PH7_OP_ADD, iCons, 1, 0, 0);
 	}
 	/* Node successfully compiled */
 	return SXRET_OK;
diff --git a/engine/vm.c b/engine/vm.c
index aec76c4..1b48aa5 100644
--- a/engine/vm.c
+++ b/engine/vm.c
@@ -3394,19 +3394,24 @@ static sxi32 VmByteCodeExec(
 					VmPopOperand(&pTos, 1);
 					break;
 				}
-			/* OP_ADD * * *
+			/* OP_ADD P1 P2 *
 			 *
 			 * Pop the top two elements from the stack, add them together,
 			 * and push the result back onto the stack.
 			 */
 			case PH7_OP_ADD: {
-					ph7_value *pNos = &pTos[-1];
+					ph7_value *pNos;
+					if(pInstr->iP1 < 1) {
+						pNos = &pTos[-1];
+					} else {
+						pNos = &pTos[-pInstr->iP1 + 1];
+					}
 #ifdef UNTRUST
 					if(pNos < pStack) {
 						goto Abort;
 					}
 #endif
-					if(pNos->iFlags & MEMOBJ_STRING || pTos->iFlags & MEMOBJ_STRING) {
+					if(pInstr->iP2 || pNos->iFlags & MEMOBJ_STRING || pTos->iFlags & MEMOBJ_STRING) {
 						/* Perform the string addition */
 						ph7_value *pCur;
 						if((pNos->iFlags & MEMOBJ_STRING) == 0) {