From: Aleksey Demakov <ademakov@gmail.com>
Date: Sat, 9 Sep 2006 05:21:03 +0000 (+0000)
Subject: add _JIT_REGS_CLOBBER_STACK flag to be used for "only" rules
X-Git-Tag: before.move.to.git~194
X-Git-Url: https://git.unchartedbackwaters.co.uk/w/?a=commitdiff_plain;h=343fad4827d26f71bfc2d928f7cdc9ab98c963f4;p=francis%2Flibjit.git

add _JIT_REGS_CLOBBER_STACK flag to be used for "only" rules
---

diff --git a/ChangeLog b/ChangeLog
index 082138c..0a4cfce 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2006-09-09  Aleksey Demakov  <ademakov@gmail.com>
+
+	* jit/jit-reg-alloc.h, jit/jit-reg-alloc.c:
+	* tools/gen-rules-parser.y: add _JIT_REGS_CLOBBER_STACK flag and use
+	it in the code genearted for "only" rules instead of the explicit
+	stack top check followed by the _jit_regs_spill_all() call.
+
 2006-09-02  Aleksey Demakov  <ademakov@gmail.com>
 
 	* jit/jit-interp.c (_jit_run_function): 
diff --git a/jit/jit-reg-alloc.c b/jit/jit-reg-alloc.c
index 01328fb..a5608a4 100644
--- a/jit/jit-reg-alloc.c
+++ b/jit/jit-reg-alloc.c
@@ -2801,9 +2801,9 @@ choose_input_order(jit_gencode_t gen, _jit_regs_t *regs)
 	}
 
 	if(regs->descs[2].value
-		&& regs->descs[2].value->in_register
-		&& regs->descs[2].value->reg == regs->descs[0].reg
-		&& regs->descs[2].value != regs->descs[1].value)
+	   && regs->descs[2].value->in_register
+	   && regs->descs[2].value->reg == regs->descs[0].reg
+	   && regs->descs[2].value != regs->descs[1].value)
 	{
 		if(regs->on_stack && regs->x87_arith)
 		{
@@ -2832,10 +2832,9 @@ choose_input_order(jit_gencode_t gen, _jit_regs_t *regs)
 	}
 
 	/* Choose between pop and no-pop instructions. */
-	if(regs->on_stack && regs->x87_arith
-	   && !regs->no_pop && !regs->clobber_all
-	   && regs->descs[1].value
-	   && regs->descs[2].value)
+	if(regs->on_stack && regs->x87_arith && !regs->no_pop
+	   && !regs->clobber_all && !regs->clobber_stack
+	   && regs->descs[1].value && regs->descs[2].value)
 	{
 		/* Determine if we might want to keep either of input values
 		   in registers after the instruction completion. */
@@ -3971,6 +3970,7 @@ _jit_regs_init(jit_gencode_t gen, _jit_regs_t *regs, int flags)
 	int index;
 
 	regs->clobber_all = (flags & _JIT_REGS_CLOBBER_ALL) != 0;
+	regs->clobber_stack = (flags & _JIT_REGS_CLOBBER_STACK) != 0;
 	regs->ternary = (flags & _JIT_REGS_TERNARY) != 0;
 	regs->branch = (flags & _JIT_REGS_BRANCH) != 0;
 	regs->copy = (flags & _JIT_REGS_COPY) != 0;
@@ -3998,7 +3998,7 @@ _jit_regs_init(jit_gencode_t gen, _jit_regs_t *regs, int flags)
 
 	/* Set clobber flags. */
 	regs->clobber = jit_regused_init;
-	if(regs->clobber_all)
+	if(regs->clobber_all || regs->clobber_stack)
 	{
 		for(index = 0; index < JIT_NUM_REGS; index++)
 		{
@@ -4007,7 +4007,10 @@ _jit_regs_init(jit_gencode_t gen, _jit_regs_t *regs, int flags)
 			{
 				continue;
 			}
-			jit_reg_set_used(regs->clobber, index);
+			if(regs->clobber_all || IS_STACK_REG(index))
+			{
+				jit_reg_set_used(regs->clobber, index);
+			}
 		}
 	}
 
diff --git a/jit/jit-reg-alloc.h b/jit/jit-reg-alloc.h
index 2695e57..55f0323 100644
--- a/jit/jit-reg-alloc.h
+++ b/jit/jit-reg-alloc.h
@@ -86,6 +86,7 @@ void _jit_regs_get_reg_pair(jit_gencode_t gen, int not_this1, int not_this2,
 #define _JIT_REGS_COMMUTATIVE		0x0040
 #define _JIT_REGS_REVERSIBLE		0x0080
 #define _JIT_REGS_FREE_DEST		0x0100
+#define _JIT_REGS_CLOBBER_STACK		0x0200
 
 /*
  * Flags for _jit_regs_init_dest(), _jit_regs_init_value1(), and
@@ -140,6 +141,7 @@ typedef struct
 typedef struct
 {
 	unsigned	clobber_all : 1;
+	unsigned	clobber_stack : 1;
 	unsigned	ternary : 1;
 	unsigned	branch : 1;
 	unsigned	copy : 1;
diff --git a/tools/gen-rules-parser.y b/tools/gen-rules-parser.y
index 95b48b0..3162210 100644
--- a/tools/gen-rules-parser.y
+++ b/tools/gen-rules-parser.y
@@ -87,11 +87,6 @@ static int gensel_new_inst_type = 0;
 static int gensel_reserve_space = 32;
 static int gensel_reserve_more_space = 128;
 
-/*
- * First register in a stack arrangement.
- */
-static int gensel_first_stack_reg = 8;	/* st0 under x86 */
-
 /*
  * Maximal number of input values in a pattern.
  */
@@ -1133,17 +1128,6 @@ static void gensel_output_clauses(gensel_clause_t clauses, gensel_option_t optio
 			printf("\telse\n\t{\n");
 		}
 
-		if(gensel_search_option(options, GENSEL_OPT_STACK)
-		   && gensel_search_option(options, GENSEL_OPT_ONLY))
-		{
-			printf("\t\tif(!_jit_regs_is_top(gen, insn->value1) ||\n");
-			printf("\t\t   _jit_regs_num_used(gen, %d) != 1)\n",
-			       gensel_first_stack_reg);
-			printf("\t\t{\n");
-			printf("\t\t\t_jit_regs_spill_all(gen);\n");
-			printf("\t\t}\n");
-		}
-
 		if(gensel_search_option(options, GENSEL_OPT_BINARY_BRANCH)
 		   || gensel_search_option(options, GENSEL_OPT_UNARY_BRANCH))
 		{
@@ -1228,6 +1212,18 @@ static void gensel_output_clauses(gensel_clause_t clauses, gensel_option_t optio
 				}
 				printf("_JIT_REGS_STACK");
 			}
+			if(gensel_search_option(options, GENSEL_OPT_ONLY))
+			{
+				if(seen_option)
+				{
+					printf(" | ");
+				}
+				else
+				{
+					seen_option = 1;
+				}
+				printf("_JIT_REGS_CLOBBER_STACK");
+			}
 			if(gensel_search_option(options, GENSEL_OPT_X87ARITH))
 			{
 				if(seen_option)