codea: super mega opt fuer einen sub spezialfall

diff --git a/codea/code.bfe b/codea/code.bfe
index 14cde11d6ab5ce0108f0a7807a2d1c5488e69c78..6184569f7b35716cc94dddc8211854275171cfa0 100644 (file)
--- a/codea/code.bfe
+++ b/codea/code.bfe
@@ -149,6 +149,16 @@ void gen_lea(struct treenode *bnode, short e)
        }
 }
 
+void gen_subspecial(struct treenode *bnode)
+{
+       /* tritt z.b. bei snafu_05.0 auf */
+       printf("\t//gen_subspecial\n");
+       KIDREG2ID(0);
+       KIDKIDREG2PARM(1,0);
+       printf("\tsubq %%%s, %%%s\n", KIDKID_REG(1,0), BN_REG);
+       printf("\taddq %%%s, %%%s\n", KIDKID_REG(1,1), BN_REG);
+}
+
 %}
 
 %start begin
@@ -171,6 +181,8 @@ expr: O_SUB(expr,imm)    # 2 # gen_e_imm(bnode, "subq");
 expr: O_SUB(imm,expr)  # 2 # gen_imm_eno(bnode, "subq");
 expr: O_SUB(imm,O_FIELD(expr)) # 2 # gen_imm_field(bnode);
 
+expr: O_SUB(expr,O_SUB(O_ID,expr)) # 2 # gen_subspecial(bnode);
+
 expr: O_SUB(expr,O_MUL(O_MONE,expr)) # 1 # gen_lea(bnode,0);
 expr: O_SUB(expr,O_MUL(O_MTWO,expr)) # 1 # gen_lea(bnode,0);
 expr: O_SUB(expr,O_MUL(O_MFOUR,expr)) # 1 # gen_lea(bnode,0);