From: Bernhard Urban <lewurm@gmail.com>
Date: Sun, 20 Jun 2010 15:06:04 +0000 (+0200)
Subject: gesamt: noch zwei optimierungen ->
X-Git-Url: http://wien.tomnetworks.com/gitweb/?p=uebersetzerbau-ss10.git;a=commitdiff_plain;h=d9e004e6b5b1a6c12bbee39d34df312e6b4e711e

gesamt: noch zwei optimierungen ->
1. nicht poppen wenn nach dem call unmittelbar ein ret folgt
2. bei "methode xx() return bla() end;" kann man sich stack aufbauen und sogar
call/ret sparen indem man einen jmp zu bla macht.
---

diff --git a/gesamt/chelper.c b/gesamt/chelper.c
index dd345b0..570c473 100644
--- a/gesamt/chelper.c
+++ b/gesamt/chelper.c
@@ -15,6 +15,7 @@ static char *regs8l[] = {"al", "r10b", "r11b", "r9b"};
 /* ja, dirty.. */
 static char *akt_func_name = (char*) NULL;
 static char need_stack = 0;
+static int call_s = 0;
 
 void func_header(char *s, int vars, int parms, int call)
 {
@@ -23,7 +24,8 @@ void func_header(char *s, int vars, int parms, int call)
 	akt_func_name = s;
 
 	need_stack = (vars || parms) && call;
-	if(need_stack) {
+	call_s = call;
+	if(need_stack && (call != -1)) {
 		printf("\tenter $%d, $0\n", 8*(vars + parms + 2 /* fuer rax und r10 */));
 	}
 }
@@ -35,9 +37,11 @@ char *get_func_name(void)
 
 void func_footer(void)
 {
-	if(need_stack)
-		printf("\tleave\n");
-	printf("\tret\n\n\n");
+	if(call_s != -1) {
+		if(need_stack)
+			printf("\tleave\n");
+		printf("\tret\n\n\n");
+	}
 }
 
 void move(char *src, char *dst)
diff --git a/gesamt/code.bfe b/gesamt/code.bfe
index fb00447..cad2d58 100644
--- a/gesamt/code.bfe
+++ b/gesamt/code.bfe
@@ -187,11 +187,11 @@ void assign_var(struct treenode *bnode)
 	printf("\tsub $%d, %%%s\n", KIDKID_VAL(0,1), KID_REG(1));
 }
 
-void make_call(struct treenode *bnode)
+void make_call(struct treenode *bnode, short skippop)
 {
 	short *sc = bnode->sc;
 	int j, off = 0;
-	printf("\t//params pushen\n");
+	printf("\t//params pushen (skippop: %d)\n", skippop);
 	for(j = 0; j < bnode->soffset; j++) {
 		if(sc[j] == 1)
 			printf("\txchg %%%s, %d(%%rsp)\n", param_reg(j), (j - off)*8);
@@ -218,11 +218,15 @@ void make_call(struct treenode *bnode)
 	printf("\tcall %s\n", bnode->name);
 	if(strcmp(BN_REG, "rax")!=0) {
 		move("rax", BN_REG);
+		if(skippop)
+			goto cleanup;
 		if(strcmp(BN_REG, "r10")!=0) {
 			printf("\tpopq %%r10\n");
 		}
 		printf("\tpopq %%rax\n");
 	}
+	if(skippop)
+		goto cleanup;
 
 	printf("\t//vars poppen\n");
 	for(j = bnode->soffset + bnode->vars - 1; j > bnode->soffset - 1; j--) {
@@ -240,6 +244,7 @@ void make_call(struct treenode *bnode)
 			printf("\tpopq %%%s\n", param_reg(j));
 	}
 
+cleanup:
 	/* clear stack_control array */
 	for(j = 0; j < sizeof sc / sizeof sc[0]; j++)
 		sc[j] = 0;
@@ -281,6 +286,8 @@ void gen_sub_field(struct treenode *bnode)
 	printf("\tsub $%d, %d(%%%s)\n", bnode->kids[0]->kids[1]->val, bnode->kids[1]->soffset * 8, KIDKID_REG(1,0));
 }
 
+int was_already_in_bfe = 0;
+
 %}
 
 %start begin
@@ -288,10 +295,12 @@ void gen_sub_field(struct treenode *bnode)
 
 %%
 
-begin: ret # 0 # printf("\n");
-begin: assign # 0 #
-begin: ifstat # 0 #
-begin: expr # 0 #
+begin: ret # 0 # printf("\n"); was_already_in_bfe = 1;
+begin: assign # 0 # was_already_in_bfe = 1;
+begin: ifstat # 0 # was_already_in_bfe = 1;
+begin: expr # 0 # was_already_in_bfe = 1;
+begin: O_RET(O_CALL(O_NOTHING, O_ARG(O_NOTHING, O_NOTHING))) # 1 # if(was_already_in_bfe == 0) { printf("\tjmp %s\n", bnode->kids[0]->name); } else { make_call(bnode->kids[0], 1); } was_already_in_bfe = 1;
+begin: O_RET(O_CALL(expr,expr)) # 1 # make_call(bnode->kids[0], 1); was_already_in_bfe = 1;
 
 
 assign: O_ASSIGN(expr, O_ID) # 1 # KIDREG2PARM(1); printf("\tmovq %%%s, %%%s\n", BN_REG, KID_REG(1));
@@ -321,7 +330,7 @@ expr: O_ID # 0 #
 expr: imm # 1 # moveimm(BN_VAL, BN_REG);
 expr: O_BOOL(expr) # 0 #
 
-expr: O_CALL(expr,expr) # 0 # make_call(bnode);
+expr: O_CALL(expr,expr) # 2 # make_call(bnode, 0);
 expr: O_ARG(expr,expr) # 1 # prep_arg(bnode, 1);
 expr: O_ARG(O_ID,expr) # 1 # prep_arg(bnode, 0);
 expr: O_ARG(expr,O_ID) # 1 # prep_arg(bnode, 2);
diff --git a/gesamt/parser.y b/gesamt/parser.y
index 5dba8e0..4e7400c 100644
--- a/gesamt/parser.y
+++ b/gesamt/parser.y
@@ -7,6 +7,24 @@
 	#include "tree.h"
 
 	#define MAX(A,B) (A > B ? A : B)
+
+	/* funktioniert nicht fuer skinner33_00.0 @ gesamt (aber dafuer fuer ca.0) */
+	int ret_opt(struct treenode *x, int call)
+	{
+		if(x->op == O_RET && x->kids[0] != TREENULL) {
+			x = x->kids[0];
+			if(x->op == O_CALL && x->kids[0] != TREENULL && x->kids[1] !=
+					TREENULL && x->kids[0]->op == O_NOTHING) {
+				x = x->kids[1];
+				if(x->op == O_ARG && x->kids[0] != TREENULL && x->kids[1] !=
+						TREENULL && x->kids[0]->op == O_NOTHING &&
+						x->kids[1]->op == O_NOTHING) {
+					return -1;
+				}
+			}
+		}
+		return call;
+	}
 %}
 
 %start Input
@@ -153,7 +171,7 @@ Statseq:
 		@i @Statseq.0.lblcnt_out@ = @Statseq.1.lblcnt_out@;
 		@i @Statseq.0.vars_out@ = @Statseq.1.vars_out@;
 
-		@i @Statseq.0.call@ = @Statement.call@ || @Statseq.1.call@;
+		@i @Statseq.0.call@ = @Statement.call@ | @Statseq.1.call@;
 	  @}
 
 	|
@@ -299,6 +317,8 @@ Statement:
 		xxputsin(@Expr.s@,)
 
 		@i @Statement.node@ = new_node(O_RET, @Expr.node@, TREENULL);
+		@i @Statement.call@ = ret_opt(@Statement.node@, @Expr.call@);
+
 		@reg @Statement.node@->reg = @Expr.node@->reg = next_reg((char *)NULL, @Expr.gparamges@);
 
 		@gen write_tree(@Statement.node@, 0); burm_label(@Statement.node@); burm_reduce(@Statement.node@, 1); func_footer();