From: uz <uz@b7a2c559-68d2-44c3-8de9-860c34a00d81>
Date: Thu, 15 Oct 2009 10:21:50 +0000 (+0000)
Subject: If a conditional branch as an unconditional jump as target, that doesn't jump
X-Git-Tag: V2.13.1~157
X-Git-Url: https://git.sur5r.net/?a=commitdiff_plain;h=635fae97fbb7dc99d84b1326c77f1eeb1ba61370;p=cc65

If a conditional branch as an unconditional jump as target, that doesn't jump
to a function-internal label, don't replace the jump target with the final
one, because this has no advantages and makes the code larger.


git-svn-id: svn://svn.cc65.org/cc65/trunk@4367 b7a2c559-68d2-44c3-8de9-860c34a00d81
---

diff --git a/src/cc65/codeopt.c b/src/cc65/codeopt.c
index cdf0c193f..e5bf23f68 100644
--- a/src/cc65/codeopt.c
+++ b/src/cc65/codeopt.c
@@ -1674,7 +1674,6 @@ static unsigned RunOptGroup3 (CodeSeg* S)
        	C += RunOptFunc (S, &DOptBoolTrans, 1);
        	C += RunOptFunc (S, &DOptJumpTarget1, 1);
        	C += RunOptFunc (S, &DOptJumpTarget2, 1);
-       	C += RunOptFunc (S, &DOptJumpTarget3, 1);
        	C += RunOptFunc (S, &DOptCondBranches1, 1);
        	C += RunOptFunc (S, &DOptCondBranches2, 1);
        	C += RunOptFunc (S, &DOptRTSJumps1, 1);
@@ -1689,6 +1688,7 @@ static unsigned RunOptGroup3 (CodeSeg* S)
        	C += RunOptFunc (S, &DOptCmp9, 1);
        	C += RunOptFunc (S, &DOptTest1, 1);
         C += RunOptFunc (S, &DOptLoad1, 1);
+       	C += RunOptFunc (S, &DOptJumpTarget3, 1);       /* After OptCondBranches2 */
        	C += RunOptFunc (S, &DOptUnusedLoads, 1);
        	C += RunOptFunc (S, &DOptUnusedStores, 1);
        	C += RunOptFunc (S, &DOptDupLoads, 1);
diff --git a/src/cc65/coptind.c b/src/cc65/coptind.c
index 81037b6fa..abb415e82 100644
--- a/src/cc65/coptind.c
+++ b/src/cc65/coptind.c
@@ -430,14 +430,24 @@ unsigned OptJumpCascades (CodeSeg* S)
 	/* Get this entry */
 	CodeEntry* E = CS_GetEntry (S, I);
 
-       	/* Check if it's a branch, if it has a jump label, if this jump
-	 * label is not attached to the instruction itself, and if the
-	 * target instruction is itself a branch.
+       	/* Check:
+         *   - if it's a branch,
+         *   - if it has a jump label,
+         *   - if this jump label is not attached to the instruction itself,
+         *   - if the target instruction is itself a branch,
+         *   - if either the first branch is unconditional or the target of
+         *     the second branch is internal to the function.
+         * The latter condition will avoid conditional branches to targets
+         * outside of the function (usually incspx), which won't simplify the
+         * code, since conditional far branches are emulated by a short branch
+         * around a jump.
 	 */
-     	if ((E->Info & OF_BRA) != 0        &&
-	    (OldLabel = E->JumpTo) != 0    &&
-	    (N = OldLabel->Owner) != E     &&
-	    (N->Info & OF_BRA) != 0) {
+     	if ((E->Info & OF_BRA) != 0             &&
+	    (OldLabel = E->JumpTo) != 0         &&
+	    (N = OldLabel->Owner) != E          &&
+	    (N->Info & OF_BRA) != 0             &&
+            ((E->Info & OF_CBRA) == 0   ||
+             N->JumpTo != 0)) {        
 
 	    /* Check if we can use the final target label. This is the case,
 	     * if the target branch is an absolut branch, or if it is a