Implement support for unlimited number of gsharedvt arg trampolines.

mono/mini/aot-compiler.c

@@ -989,6 +989,31 @@ arch_emit_specific_trampoline_pages (MonoAotCompile *acfg)
 		g_assert (code - buf == 8);
 		emit_bytes (acfg, buf, code - buf);
 	}
+
+	/*
+	 * gsharedvt arg trampolines: see arch_emit_gsharedvt_arg_trampoline ()
+	 */
+	emit_global (acfg, "gsharedvt_arg_trampolines_page", TRUE);
+	emit_label (acfg, "gsharedvt_arg_trampolines_page");
+	code = buf;
+	ARM_PUSH (code, (1 << ARMREG_R0) | (1 << ARMREG_R1) | (1 << ARMREG_R2) | (1 << ARMREG_R3) | (1 << ARMREG_LR));
+	imm8 = mono_arm_is_rotated_imm8 (mono_pagesize (), &rot_amount);
+	ARM_SUB_REG_IMM (code, ARMREG_IP, ARMREG_IP, imm8, rot_amount);
+	ARM_LDR_IMM (code, ARMREG_LR, ARMREG_IP, -8);
+	ARM_LDR_IMM (code, ARMREG_PC, ARMREG_IP, -4);
+	g_assert (code - buf == COMMON_TRAMP_SIZE);
+	/* Emit it */
+	emit_bytes (acfg, buf, code - buf);
+
+	for (i = 0; i < count; ++i) {
+		code = buf;
+		ARM_MOV_REG_REG (code, ARMREG_IP, ARMREG_PC);
+		ARM_B (code, 0);
+		arm_patch (code - 4, code - COMMON_TRAMP_SIZE - 8 * (i + 1));
+		g_assert (code - buf == 8);
+		emit_bytes (acfg, buf, code - buf);
+	}
+
 	/* now the imt trampolines: each specific trampolines puts in the ip register
 	 * the instruction pointer address, so the generic trampoline at the start of the page
 	 * subtracts 4096 to get to the data page and loads the values
@@ -5772,6 +5797,7 @@ mono_aot_parse_options (const char *aot_options, MonoAotOptions *opts)
 		opts->ntrampolines = 0;
 		opts->nrgctx_trampolines = 0;
 		opts->nimt_trampolines = 0;
+		opts->ngsharedvt_arg_trampolines = 0;
 	}
 	g_strfreev (args);
 }

mono/mini/aot-runtime.c

@@ -4021,7 +4021,7 @@ static TrampolinePage* trampoline_pages [MONO_AOT_TRAMP_NUM];
  * the minimum for the common code must be at least sizeof(TrampolinePage), since we store the page info at the
  * beginning of the data page.
  */
-static const int trampolines_pages_code_offsets [MONO_AOT_TRAMP_NUM] = {16, 16, 72};
+static const int trampolines_pages_code_offsets [MONO_AOT_TRAMP_NUM] = {16, 16, 72, 16};
 
 static unsigned char*
 get_new_trampoline_from_page (int tramp_type)
@@ -4060,6 +4060,8 @@ get_new_trampoline_from_page (int tramp_type)
 		tpage = load_function (amodule, "rgctx_trampolines_page");
 	else if (tramp_type == MONO_AOT_TRAMP_IMT_THUNK)
 		tpage = load_function (amodule, "imt_trampolines_page");
+	else if (tramp_type == MONO_AOT_TRAMP_GSHAREDVT_ARG)
+		tpage = load_function (amodule, "gsharedvt_arg_trampolines_page");
 	else
 		g_error ("Incorrect tramp type for trampolines page");
 	g_assert (tpage);
@@ -4172,6 +4174,21 @@ get_new_imt_trampoline_from_page (gpointer arg)
 
 }
 
+static gpointer
+get_new_gsharedvt_arg_trampoline_from_page (gpointer tramp, gpointer arg)
+{
+	void *code;
+	gpointer *data;
+
+	code = get_new_trampoline_from_page (MONO_AOT_TRAMP_GSHAREDVT_ARG);
+
+	data = (gpointer*)((char*)code - mono_pagesize ());
+	data [0] = arg;
+	data [1] = tramp;
+	/*g_warning ("new rgctx trampoline at %p for data %p, tramp %p (stored at %p)", code, arg, tramp, data);*/
+	return code;
+}
+
 /* Return a given kind of trampoline */
 static gpointer
 get_numerous_trampoline (MonoAotTrampoline tramp_type, int n_got_slots, MonoAotModule **out_amodule, guint32 *got_offset, guint32 *out_tramp_size)
@@ -4428,10 +4445,14 @@ mono_aot_get_gsharedvt_arg_trampoline (gpointer arg, gpointer addr)
 	guint8 *code;
 	guint32 got_offset;
 
-	code = get_numerous_trampoline (MONO_AOT_TRAMP_GSHAREDVT_ARG, 2, &amodule, &got_offset, NULL);
+	if (USE_PAGE_TRAMPOLINES) {
+		code = get_new_gsharedvt_arg_trampoline_from_page (addr, arg);
+	} else {
+		code = get_numerous_trampoline (MONO_AOT_TRAMP_GSHAREDVT_ARG, 2, &amodule, &got_offset, NULL);
 
-	amodule->got [got_offset] = arg;
-	amodule->got [got_offset + 1] = addr; 
+		amodule->got [got_offset] = arg;
+		amodule->got [got_offset + 1] = addr; 
+	}
 
 	/* The caller expects an ftnptr */
 	return mono_create_ftnptr (mono_domain_get (), code);