# HG changeset patch
# User Stefan Ring <stefan@complang.tuwien.ac.at>
# Date 1213041161 -7200
# Branch subtype
# Node ID f4d2cd262a58a830d9f1ddc7f1e783e6b118d467
# Parent  b8487bde49f1dafb6e1817915d86a3fc506cabfc
* src/vm/builtin.c: Added fast_subtype_check.
(builtin_fast_canstore, builtin_fast_canstore_onedim,
builtin_fast_canstore_onedim_class): Using fast subtype check. Don't need
to lock linker_classrenumber_lock anymore.
* src/vm/builtin.h: Added fast_subtype_check.

* src/vm/jit/emit-common.h: Added more branch labels.

* src/vm/jit/x86_64/codegen.c (gen_method): New subtype checking code.
* src/vm/jit/x86_64/codegen.h: Added some new mnemonics.
* src/vm/jit/x86_64/emit.c: New mnemonics.
(emit_classcast_check): New branch modes.
* src/vm/jit/x86_64/emit.h: New mnemonics.
* src/vmcore/class.c (class_isanysubclass): Using fast_subtype_check.

* src/vmcore/linker.c: Removed linker_classrenumber_lock.
(build_display): Implemented.
(link_class_intern, link_array, linker_compute_subclasses): Minor changes.

* src/vmcore/linker.h: Removed linker_compute_subclasses.
Added subtype-related fields to _vftbl.

* src/cacaoh/dummy.c: Added fast_subtype_check (link dependency).

diff -r b8487bde49f1 -r f4d2cd262a58 src/cacaoh/dummy.c
--- a/src/cacaoh/dummy.c	Mon Jun 09 17:31:43 2008 +0200
+++ b/src/cacaoh/dummy.c	Mon Jun 09 21:52:41 2008 +0200
@@ -158,6 +158,12 @@
 {
 	vm_abort("builtin_clone: Not implemented.");
 	return NULL;
+}
+
+bool fast_subtype_check(struct _vftbl *s, struct _vftbl *t)
+{
+	vm_abort("fast_subtype_check: Not implemented.");
+	return 0;
 }
 
 bool builtin_isanysubclass(classinfo *sub, classinfo *super)
diff -r b8487bde49f1 -r f4d2cd262a58 src/vm/builtin.c
--- a/src/vm/builtin.c	Mon Jun 09 17:31:43 2008 +0200
+++ b/src/vm/builtin.c	Mon Jun 09 21:52:41 2008 +0200
@@ -667,6 +667,19 @@
 
 *******************************************************************************/
 
+bool fast_subtype_check(struct _vftbl *s, struct _vftbl *t)
+{
+	int i;
+	if (s->subtype_display[t->subtype_depth] == t)
+		return true;
+	if (t->subtype_offset != OFFSET(vftbl_t, subtype_display[DISPLAY_SIZE]))
+		return false;
+	for (i=0; i<s->subtype_overflow_length; i++)
+		if (s->subtype_overflow[i] == t)
+			return true;
+	return false;
+}
+
 bool builtin_fast_canstore(java_objectarray_t *oa, java_object_t *o)
 {
 	arraydescriptor *desc;
@@ -699,8 +712,6 @@
 		if (valuevftbl == componentvftbl)
 			return 1;
 
-		LOCK_MONITOR_ENTER(linker_classrenumber_lock);
-
 		baseval = componentvftbl->baseval;
 
 		if (baseval <= 0) {
@@ -710,11 +721,8 @@
 					  (valuevftbl->interfacetable[baseval] != NULL));
 		}
 		else {
-			diffval = valuevftbl->baseval - componentvftbl->baseval;
-			result  = diffval <= (uint32_t) componentvftbl->diffval;
+			result = fast_subtype_check(valuevftbl, componentvftbl);
 		}
-
-		LOCK_MONITOR_EXIT(linker_classrenumber_lock);
 	}
 	else if (valuedesc == NULL) {
 		/* {oa has dimension > 1} */
@@ -766,8 +774,6 @@
 	if (valuevftbl == elementvftbl)
 		return 1;
 
-	LOCK_MONITOR_ENTER(linker_classrenumber_lock);
-
 	baseval = elementvftbl->baseval;
 
 	if (baseval <= 0) {
@@ -776,11 +782,8 @@
 				  (valuevftbl->interfacetable[baseval] != NULL));
 	}
 	else {
-		diffval = valuevftbl->baseval - elementvftbl->baseval;
-		result  = diffval <= (uint32_t) elementvftbl->diffval;
+		result = fast_subtype_check(valuevftbl, elementvftbl);
 	}
-
-	LOCK_MONITOR_EXIT(linker_classrenumber_lock);
 
 	return result;
 }
@@ -815,12 +818,7 @@
 	if (valuevftbl == elementvftbl)
 		return 1;
 
-	LOCK_MONITOR_ENTER(linker_classrenumber_lock);
-
-	diffval = valuevftbl->baseval - elementvftbl->baseval;
-	result  = diffval <= (uint32_t) elementvftbl->diffval;
-
-	LOCK_MONITOR_EXIT(linker_classrenumber_lock);
+	result = fast_subtype_check(valuevftbl, elementvftbl);
 
 	return result;
 }
diff -r b8487bde49f1 -r f4d2cd262a58 src/vm/builtin.h
--- a/src/vm/builtin.h	Mon Jun 09 17:31:43 2008 +0200
+++ b/src/vm/builtin.h	Mon Jun 09 21:52:41 2008 +0200
@@ -119,6 +119,8 @@
  * (The BUILTIN* opcodes are ICMD_BUILTIN1, ICMD_BUILTIN2 and
  * ICMD_BUILTIN3.)
  */
+
+bool fast_subtype_check(struct _vftbl *, struct _vftbl *);
 
 bool builtin_instanceof(java_handle_t *obj, classinfo *class);
 /* NOT AN OP */
diff -r b8487bde49f1 -r f4d2cd262a58 src/vm/jit/emit-common.h
--- a/src/vm/jit/emit-common.h	Mon Jun 09 17:31:43 2008 +0200
+++ b/src/vm/jit/emit-common.h	Mon Jun 09 21:52:41 2008 +0200
@@ -45,6 +45,10 @@
 #define BRANCH_LABEL_4    4
 #define BRANCH_LABEL_5    5
 #define BRANCH_LABEL_6    6
+#define BRANCH_LABEL_7    7
+#define BRANCH_LABEL_8    8
+#define BRANCH_LABEL_9    9
+#define BRANCH_LABEL_10  10
 
 
 /* constant range macros ******************************************************/
diff -r b8487bde49f1 -r f4d2cd262a58 src/vm/jit/x86_64/codegen.c
--- a/src/vm/jit/x86_64/codegen.c	Mon Jun 09 17:31:43 2008 +0200
+++ b/src/vm/jit/x86_64/codegen.c	Mon Jun 09 21:52:41 2008 +0200
@@ -2486,6 +2486,8 @@
 				classinfo *super;
 				s4         superindex;
 
+				s4 looptarget;
+
 				if (INSTRUCTION_IS_UNRESOLVED(iptr)) {
 					super      = NULL;
 					superindex = 0;
@@ -2494,9 +2496,6 @@
 					super      = iptr->sx.s23.s3.c.cls;
 					superindex = super->index;
 				}
-
-				if ((super == NULL) || !(super->flags & ACC_INTERFACE))
-					CODEGEN_CRITICAL_SECTION_NEW;
 
 				s1 = emit_load_s1(jd, iptr, REG_ITMP1);
 
@@ -2567,37 +2566,66 @@
 						disp = dseg_add_address(cd, super->vftbl);
 					}
 
-					M_ALD(REG_ITMP2, s1, OFFSET(java_object_t, vftbl));
-					M_ALD(REG_ITMP3, RIP, disp);
+					if (s1 == REG_ITMP1)
+						M_AST(REG_ITMP1, REG_SP, -8); /* store in red zone */
 
-					CODEGEN_CRITICAL_SECTION_START;
+					M_ALD(REG_ITMP1, s1, OFFSET(java_object_t, vftbl));
+					M_ALD(REG_ITMP2, RIP, disp);
 
-					M_ILD(REG_ITMP2, REG_ITMP2, OFFSET(vftbl_t, baseval));
+					if (super == NULL || super->vftbl->subtype_depth >= DISPLAY_SIZE) {
+					M_ALD(REG_ITMP3, REG_ITMP2, OFFSET(vftbl_t, subtype_offset));
 
-					/*  					if (s1 != REG_ITMP1) { */
-					/*  						emit_movl_membase_reg(cd, REG_ITMP3, */
-					/*  												OFFSET(vftbl_t, baseval), */
-					/*  												REG_ITMP1); */
-					/*  						emit_movl_membase_reg(cd, REG_ITMP3, */
-					/*  												OFFSET(vftbl_t, diffval), */
-					/*  												REG_ITMP3); */
-					/*  #if defined(ENABLE_THREADS) */
-					/*  						codegen_threadcritstop(cd, cd->mcodeptr - cd->mcodebase); */
-					/*  #endif */
-					/*  						emit_alu_reg_reg(cd, ALU_SUB, REG_ITMP1, REG_ITMP2); */
+					*(cd->mcodeptr++) = 0x4e;
+					*(cd->mcodeptr++) = 0x3b;
+					*(cd->mcodeptr++) = 0x14;
+					*(cd->mcodeptr++) = 0x18;
+					/* cmp (ITMP1, ITMP3, 1), ITMP2 */
 
-					/*  					} else { */
+					emit_label_beq(cd, BRANCH_LABEL_6); /* good */
 
-					M_ILD(REG_ITMP3, REG_ITMP3, OFFSET(vftbl_t, baseval));
-					M_ISUB(REG_ITMP3, REG_ITMP2);
-					M_ALD(REG_ITMP3, RIP, disp);
-					M_ILD(REG_ITMP3, REG_ITMP3, OFFSET(vftbl_t, diffval));
-					/*  					} */
+					M_LCMP_IMM(OFFSET(vftbl_t, subtype_display[DISPLAY_SIZE]), REG_ITMP3);
+					emit_classcast_check(cd, iptr, BRANCH_NE, REG_ITMP3, s1);
 
-					CODEGEN_CRITICAL_SECTION_END;
+					/* use red zone */
+					M_AST(REG_ITMP2, REG_SP, -16);
+					M_AST_IMM32(0, REG_SP, -24);
+					M_ALD(REG_ITMP3, REG_ITMP1, OFFSET(vftbl_t, subtype_overflow));
+					looptarget = cd->mcodeptr - cd->mcodebase;
 
-					M_ICMP(REG_ITMP3, REG_ITMP2);
-					emit_classcast_check(cd, iptr, BRANCH_UGT, REG_ITMP3, s1);
+					M_ALD(REG_ITMP2, REG_SP, -24);
+					M_ICMP_MEMBASE(REG_ITMP1, OFFSET(vftbl_t, subtype_overflow_length), REG_ITMP2);
+
+					emit_classcast_check(cd, iptr, BRANCH_GE, REG_ITMP3, s1);
+
+					*(cd->mcodeptr++) = 0x4f;
+					*(cd->mcodeptr++) = 0x8b;
+					*(cd->mcodeptr++) = 0x14;
+					*(cd->mcodeptr++) = 0xd3;
+					/* movq (ITMP3, ITMP2, 8), ITMP2 */
+
+					M_LCMP_MEMBASE(REG_SP, -16, REG_ITMP2);
+					emit_label_beq(cd, BRANCH_LABEL_7); /* good, pop */
+
+					M_LINC_MEMBASE(REG_SP, -24);
+					M_JMP_IMM2(looptarget - (cd->mcodeptr - cd->mcodebase) - 2); /* 1 byte displacement */
+
+					emit_label(cd, BRANCH_LABEL_7);
+
+					emit_label(cd, BRANCH_LABEL_6);
+					}
+					else {
+						assert(super->vftbl->subtype_offset < 0x80);
+						*(cd->mcodeptr++) = 0x4c;
+						*(cd->mcodeptr++) = 0x3b;
+						*(cd->mcodeptr++) = 0x50;
+						*(cd->mcodeptr++) = super->vftbl->subtype_offset;
+						/* cmp off(ITMP1), ITMP2 */
+
+						emit_classcast_check(cd, iptr, BRANCH_NE, REG_ITMP3, s1);
+					}
+
+					if (s1 == REG_ITMP1)
+						M_ALD(REG_ITMP1, REG_SP, -8);
 
 					if (super != NULL)
 						emit_label(cd, BRANCH_LABEL_5);
@@ -2650,6 +2678,8 @@
 			classinfo *super;
 			s4         superindex;
 
+			s4 looptarget;
+
 			if (INSTRUCTION_IS_UNRESOLVED(iptr)) {
 				super      = NULL;
 				superindex = 0;
@@ -2658,9 +2688,6 @@
 				super      = iptr->sx.s23.s3.c.cls;
 				superindex = super->index;
 			}
-
-			if ((super == NULL) || !(super->flags & ACC_INTERFACE))
-				CODEGEN_CRITICAL_SECTION_NEW;
 
 			s1 = emit_load_s1(jd, iptr, REG_ITMP1);
 			d = codegen_reg_of_dst(jd, iptr, REG_ITMP2);
@@ -2743,18 +2770,67 @@
 				M_ALD(REG_ITMP1, s1, OFFSET(java_object_t, vftbl));
 				M_ALD(REG_ITMP2, RIP, disp);
 
-				CODEGEN_CRITICAL_SECTION_START;
+				if (super == NULL || super->vftbl->subtype_depth >= DISPLAY_SIZE) {
+				M_ALD(REG_ITMP3, REG_ITMP2, OFFSET(vftbl_t, subtype_offset));
 
-				M_ILD(REG_ITMP1, REG_ITMP1, OFFSET(vftbl_t, baseval));
-				M_ILD(REG_ITMP3, REG_ITMP2, OFFSET(vftbl_t, diffval));
-				M_ILD(REG_ITMP2, REG_ITMP2, OFFSET(vftbl_t, baseval));
+				*(cd->mcodeptr++) = 0x4e;
+				*(cd->mcodeptr++) = 0x3b;
+				*(cd->mcodeptr++) = 0x14;
+				*(cd->mcodeptr++) = 0x18;
+				/* cmp (ITMP1, ITMP3, 1), ITMP2 */
 
-				CODEGEN_CRITICAL_SECTION_END;
+				emit_label_bne(cd, BRANCH_LABEL_6);
+				M_LINC(d);
+				emit_label_br(cd, BRANCH_LABEL_7); /* ende */
 
-				M_ISUB(REG_ITMP2, REG_ITMP1);
-				M_CLR(d); /* may be REG_ITMP2 */
-				M_ICMP(REG_ITMP3, REG_ITMP1);
-				M_SETULE(d);
+				emit_label(cd, BRANCH_LABEL_6);
+
+				M_LCMP_IMM(OFFSET(vftbl_t, subtype_display[DISPLAY_SIZE]), REG_ITMP3);
+				emit_label_bne(cd, BRANCH_LABEL_6); /* ende */
+
+				/* use the red zone */
+				M_AST(REG_ITMP2, REG_SP, -16);
+				M_AST_IMM32(0, REG_SP, -24);
+				M_ALD(REG_ITMP3, REG_ITMP1, OFFSET(vftbl_t, subtype_overflow));
+				looptarget = cd->mcodeptr - cd->mcodebase;
+
+				M_ALD(REG_ITMP2, REG_SP, -24);
+				M_ICMP_MEMBASE(REG_ITMP1, OFFSET(vftbl_t, subtype_overflow_length), REG_ITMP2);
+				emit_label_bge(cd, BRANCH_LABEL_8); /* ende pop */
+
+				*(cd->mcodeptr++) = 0x4f;
+				*(cd->mcodeptr++) = 0x8b;
+				*(cd->mcodeptr++) = 0x14;
+				*(cd->mcodeptr++) = 0xd3;
+				/* movq (ITMP3, ITMP2, 8), ITMP2 */
+
+				M_LCMP_MEMBASE(REG_SP, -16, REG_ITMP2);
+				emit_label_bne(cd, BRANCH_LABEL_9);
+				M_LINC(d);
+				emit_label_br(cd, BRANCH_LABEL_10); /* ende pop */
+				emit_label(cd, BRANCH_LABEL_9);
+
+				M_LINC_MEMBASE(REG_SP, -24);
+				M_JMP_IMM2(looptarget - (cd->mcodeptr - cd->mcodebase) - 2); /* 1 byte displacement */
+
+				emit_label(cd, BRANCH_LABEL_8);
+				emit_label(cd, BRANCH_LABEL_10);
+
+				emit_label(cd, BRANCH_LABEL_6);
+				emit_label(cd, BRANCH_LABEL_7);
+				}
+				else {
+					assert(super->vftbl->subtype_offset < 0x80);
+					*(cd->mcodeptr++) = 0x4c;
+					*(cd->mcodeptr++) = 0x3b;
+					*(cd->mcodeptr++) = 0x50;
+					*(cd->mcodeptr++) = super->vftbl->subtype_offset;
+					/* cmp off(ITMP1), ITMP2 */
+
+					emit_label_bne(cd, BRANCH_LABEL_6);
+					M_LINC(d);
+					emit_label(cd, BRANCH_LABEL_6);
+				}
 
 				if (super != NULL)
 					emit_label(cd, BRANCH_LABEL_5);
diff -r b8487bde49f1 -r f4d2cd262a58 src/vm/jit/x86_64/codegen.h
--- a/src/vm/jit/x86_64/codegen.h	Mon Jun 09 17:31:43 2008 +0200
+++ b/src/vm/jit/x86_64/codegen.h	Mon Jun 09 21:52:41 2008 +0200
@@ -195,6 +195,7 @@
 #define M_LMUL_IMM(a,b,c)       emit_imul_imm_reg_reg(cd, (b), (a), (c))
 
 #define M_IINC(a)               emit_incl_reg(cd, (a))
+#define M_LINC(a)               emit_incq_reg(cd, (a))
 #define M_IDEC(a)               emit_decl_reg(cd, (a))
 
 #define M_ALD(a,b,disp) \
@@ -312,6 +313,7 @@
 
 #define M_JMP(a)                emit_jmp_reg(cd, (a))
 #define M_JMP_IMM(a)            emit_jmp_imm(cd, (a))
+#define M_JMP_IMM2(a)           emit_jmp_imm2(cd, (a))
 #define M_CALL(a)               emit_call_reg(cd, (a))
 #define M_CALL_IMM(a)           emit_call_imm(cd, (a))
 #define M_RET                   M_BYTE1(0xc3)
@@ -361,6 +363,7 @@
 #define M_RDTSC                 emit_rdtsc(cd)
 
 #define M_IINC_MEMBASE(a,b)     emit_incl_membase(cd, (a), (b))
+#define M_LINC_MEMBASE(a,b)     emit_incq_membase(cd, (a), (b))
 
 #define M_IADD_MEMBASE(a,b,c)   emit_alul_reg_membase(cd, ALU_ADD, (a), (b), (c))
 #define M_IADC_MEMBASE(a,b,c)   emit_alul_reg_membase(cd, ALU_ADC, (a), (b), (c))
diff -r b8487bde49f1 -r f4d2cd262a58 src/vm/jit/x86_64/emit.c
--- a/src/vm/jit/x86_64/emit.c	Mon Jun 09 17:31:43 2008 +0200
+++ b/src/vm/jit/x86_64/emit.c	Mon Jun 09 21:52:41 2008 +0200
@@ -361,8 +361,14 @@
 		case BRANCH_LE:
 			M_BGT(8);
 			break;
+		case BRANCH_GE:
+			M_BLT(8);
+			break;
 		case BRANCH_EQ:
 			M_BNE(8);
+			break;
+		case BRANCH_NE:
+			M_BEQ(8);
 			break;
 		case BRANCH_UGT:
 			M_BULE(8);
@@ -1438,10 +1444,29 @@
 }
 
 
+void emit_incl_reg(codegendata *cd, s8 reg)
+{
+	*(cd->mcodeptr++) = 0xff;
+	emit_reg(0,(reg));
+}
+
+void emit_incq_reg(codegendata *cd, s8 reg)
+{
+	emit_rex(1,0,0,(reg));
+	*(cd->mcodeptr++) = 0xff;
+	emit_reg(0,(reg));
+}
 
 void emit_incl_membase(codegendata *cd, s8 basereg, s8 disp)
 {
 	emit_rex(0,0,0,(basereg));
+	*(cd->mcodeptr++) = 0xff;
+	emit_membase(cd, (basereg),(disp),0);
+}
+
+void emit_incq_membase(codegendata *cd, s8 basereg, s8 disp)
+{
+	emit_rex(1,0,0,(basereg));
 	*(cd->mcodeptr++) = 0xff;
 	emit_membase(cd, (basereg),(disp),0);
 }
@@ -1678,6 +1703,18 @@
 	emit_imm32((imm));
 }
 
+/* like emit_jmp_imm but allows 8 bit optimization */
+void emit_jmp_imm2(codegendata *cd, s8 imm) {
+	if (IS_IMM8(imm)) {
+		*(cd->mcodeptr++) = 0xeb;
+		emit_imm8((imm));
+	}
+	else {
+		*(cd->mcodeptr++) = 0xe9;
+		emit_imm32((imm));
+	}
+}
+
 
 void emit_jmp_reg(codegendata *cd, s8 reg) {
 	emit_rex(0,0,0,(reg));
diff -r b8487bde49f1 -r f4d2cd262a58 src/vm/jit/x86_64/emit.h
--- a/src/vm/jit/x86_64/emit.h	Mon Jun 09 17:31:43 2008 +0200
+++ b/src/vm/jit/x86_64/emit.h	Mon Jun 09 21:52:41 2008 +0200
@@ -251,7 +251,10 @@
 void emit_lea_membase_reg(codegendata *cd, s8 basereg, s8 disp, s8 reg);
 void emit_leal_membase_reg(codegendata *cd, s8 basereg, s8 disp, s8 reg);
 
+void emit_incl_reg(codegendata *cd, s8 reg);
+void emit_incq_reg(codegendata *cd, s8 reg);
 void emit_incl_membase(codegendata *cd, s8 basereg, s8 disp);
+void emit_incq_membase(codegendata *cd, s8 basereg, s8 disp);
 
 void emit_cltd(codegendata *cd);
 void emit_cqto(codegendata *cd);
diff -r b8487bde49f1 -r f4d2cd262a58 src/vmcore/class.c
--- a/src/vmcore/class.c	Mon Jun 09 17:31:43 2008 +0200
+++ b/src/vmcore/class.c	Mon Jun 09 21:52:41 2008 +0200
@@ -1591,12 +1591,7 @@
 		if (sub->flags & ACC_INTERFACE)
 			return (super == class_java_lang_Object);
 
-		LOCK_MONITOR_ENTER(linker_classrenumber_lock);
-
-		diffval = sub->vftbl->baseval - super->vftbl->baseval;
-		result  = diffval <= (uint32_t) super->vftbl->diffval;
-
-		LOCK_MONITOR_EXIT(linker_classrenumber_lock);
+		result = fast_subtype_check(sub->vftbl, super->vftbl);
 	}
 
 	return result;
diff -r b8487bde49f1 -r f4d2cd262a58 src/vmcore/linker.c
--- a/src/vmcore/linker.c	Mon Jun 09 17:31:43 2008 +0200
+++ b/src/vmcore/linker.c	Mon Jun 09 21:52:41 2008 +0200
@@ -91,8 +91,6 @@
 
 static s4 interfaceindex;       /* sequential numbering of interfaces         */
 static s4 classvalue;
-
-java_object_t *linker_classrenumber_lock;
 
 
 /* private functions **********************************************************/
@@ -164,14 +162,6 @@
 	/* Reset interface index. */
 
 	interfaceindex = 0;
-
-#if defined(ENABLE_THREADS)
-	/* create the global lock object */
-
-	linker_classrenumber_lock = NEW(java_object_t);
-
-	LOCK_INIT_OBJECT_LOCK(linker_classrenumber_lock);
-#endif
 
 	/* Link the most basic classes. */
 
@@ -556,6 +546,70 @@
    methods and interface methods.
 	
 *******************************************************************************/
+
+static int build_display_inner(classinfo *topc, classinfo *c, int i)
+{
+	int depth;
+	if (!c)
+		return 0;
+	do {
+		if (c->vftbl->arraydesc)
+		{
+			arraydescriptor *a = c->vftbl->arraydesc;
+			if (a->elementvftbl && a->elementvftbl->clazz->super)
+			{
+				classinfo *cls = a->elementvftbl->clazz->super;
+				int n;
+				for (n=0; n<a->dimension; n++)
+					cls = class_array_of(cls, true);
+				depth = build_display_inner(topc, cls, i+1);
+				break;
+			}
+			if (a->componentvftbl && a->elementvftbl)
+			{
+				depth = build_display_inner(topc, a->componentvftbl->clazz, i+1);
+				break;
+			}
+		}
+		depth = build_display_inner(topc, c->super, i+1);
+	} while (false);
+	if (depth >= DISPLAY_SIZE)
+	{
+		if (depth == DISPLAY_SIZE)
+		{
+			topc->vftbl->subtype_overflow_length = i+1;
+			topc->vftbl->subtype_overflow = malloc(sizeof(void*) * (i+1));
+#if defined(ENABLE_STATISTICS)
+			if (opt_stat)
+				count_vftbl_len += sizeof(void*) * (i+1);
+#endif
+		}
+		topc->vftbl->subtype_overflow[depth - DISPLAY_SIZE] = c->vftbl;
+		return depth + 1;
+	}
+	topc->vftbl->subtype_display[depth] = c->vftbl;
+	return depth + 1;
+}
+
+static void build_display(classinfo *c)
+{
+	int depth;
+	int i;
+
+	depth = build_display_inner(c, c, 0) - 1;
+	c->vftbl->subtype_depth = depth;
+	if (depth >= DISPLAY_SIZE)
+	{
+		c->vftbl->subtype_offset = OFFSET(vftbl_t, subtype_display[DISPLAY_SIZE]);
+	}
+	else
+	{
+		c->vftbl->subtype_offset = OFFSET(vftbl_t, subtype_display[0]) + sizeof(void*) * depth;
+		for (i=depth+1; i<=DISPLAY_SIZE; i++)
+			c->vftbl->subtype_display[i] = NULL;
+		c->vftbl->subtype_overflow_length = 0;
+	}
+}
 
 static classinfo *link_class_intern(classinfo *c)
 {
@@ -973,7 +1027,10 @@
 
 	linker_compute_subclasses(c);
 
+	/* FIXME: this is completely useless now */
 	RT_TIMING_GET_TIME(time_subclasses);
+
+	build_display(c);
 
 	/* revert the linking state and class is linked */
 
@@ -1174,8 +1231,6 @@
 
 static void linker_compute_subclasses(classinfo *c)
 {
-	LOCK_MONITOR_ENTER(linker_classrenumber_lock);
-
 #if 0 && defined(ENABLE_THREADS) && !defined(DISABLE_GC)
 	threads_stopworld();
 #endif
@@ -1183,6 +1238,7 @@
 	if (!(c->flags & ACC_INTERFACE)) {
 		c->nextsub = NULL;
 		c->sub     = NULL;
+		c->vftbl->baseval = 1; /* so it does not look like an interface */
 	}
 
 	if (!(c->flags & ACC_INTERFACE) && (c->super != NULL)) {
@@ -1191,12 +1247,6 @@
 	}
 
 	classvalue = 0;
-
-	/* compute class values */
-
-	linker_compute_class_values(class_java_lang_Object);
-
-	LOCK_MONITOR_EXIT(linker_classrenumber_lock);
 
 #if 0 && defined(ENABLE_THREADS) && !defined(DISABLE_GC)
 	threads_startworld();
diff -r b8487bde49f1 -r f4d2cd262a58 src/vmcore/linker.h
--- a/src/vmcore/linker.h	Mon Jun 09 17:31:43 2008 +0200
+++ b/src/vmcore/linker.h	Mon Jun 09 21:52:41 2008 +0200
@@ -100,6 +100,8 @@
 
 *******************************************************************************/
 
+#define DISPLAY_SIZE 4
+
 struct _vftbl {
 	methodptr   *interfacetable[1];    /* interface table (access via macro)  */
 	classinfo   *clazz;                /* class, the vtbl belongs to          */
@@ -109,6 +111,13 @@
 	s4           baseval;              /* base for runtime type check         */
 	                                   /* (-index for interfaces)             */
 	s4           diffval;              /* high - base for runtime type check  */
+
+	s4 subtype_depth;
+	ptrint subtype_offset;
+	struct _vftbl *subtype_display[DISPLAY_SIZE+1];  /* the last one is cache */
+	s4 subtype_overflow_length;
+	struct _vftbl **subtype_overflow;
+
 	s4          *interfacevftbllength; /* length of interface vftbls          */
 	methodptr    table[1];             /* class vftbl                         */
 };
@@ -133,14 +142,6 @@
 };
 
 
-/* global variables ***********************************************************/
-
-/* This lock must be taken while renumbering classes or while atomically      */
-/* accessing classes.                                                         */
-
-extern java_object_t *linker_classrenumber_lock;
-
-
 /* function prototypes ********************************************************/
 
 void       linker_preinit(void);