From 8af4b246d86df7bc906841689912534ea450cce5 Mon Sep 17 00:00:00 2001
From: Paul Oliver <contact@pauloliver.dev>
Date: Thu, 29 Feb 2024 02:29:14 +0100
Subject: Removed memory bit flags entirely.

[#28] Bit flags were exclusively a cosmetic component, not needed at
all to run the simulator. I've added a new 'render' module that takes
care of appending bit flags to rendered memory images, providing the
same aesthetic result, but only when requested.
---
 src/render.c | 93 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 93 insertions(+)
 create mode 100644 src/render.c

(limited to 'src/render.c')

diff --git a/src/render.c b/src/render.c
new file mode 100644
index 0000000..128ce3b
--- /dev/null
+++ b/src/render.c
@@ -0,0 +1,93 @@
+#include <assert.h>
+#include <stdio.h>
+#include "types.h"
+#include "memory.h"
+#include "process.h"
+#include "render.h"
+
+#define MAX_ZOOM 0x10000
+#define BLOCK_FLAG 0x40
+#define IP_FLAG 0x80
+
+static void apply_flag(
+	uint32 origin, uint32 max_pos, uint32 cell_size, uint32 address,
+	uint32 flag, uint8_p buffer
+) {
+	if (address >= origin && address < max_pos) {
+		/* Flag falls inside rendered image. We can 'and' the bit to the
+		corresponding pixel.
+		*/
+		uint32 pixel = (address - origin) / cell_size;
+		buffer[pixel] |= flag;
+	}
+}
+
+void sal_ren_get_image(
+	uint32 origin, uint32 cell_size, uint32 buff_size, uint8_p buffer
+) {
+	/* Render a 1D image of a given section of memory, at a given resolution
+	(zoom) and store it in a pre-allocated 'buffer'.
+
+	On the Salis python handler we draw memory as a 1D 'image' on the WORLD
+	page. If we were to render this image directly on python, it would be
+	excruciatingly slow, as we have to iterate over large areas of memory!
+	Therefore, this memory module comes with a built-in, super fast renderer.
+	*/
+	uint32 i;
+	uint32 max_pos;
+	assert(sal_mem_is_address_valid(origin));
+	assert(cell_size);
+	assert(cell_size <= MAX_ZOOM);
+	assert(buff_size);
+	assert(buffer);
+
+	/* We make use of openmp for multi-threaded looping. This allows even
+	faster render times, wherever openmp is supported.
+	*/
+	#pragma omp parallel for
+	for (i = 0; i < buff_size; i++) {
+		uint32 j;
+		uint32 inst_sum = 0;
+		uint32 alloc_flag = 0;
+		uint32 cell_addr = origin + (i * cell_size);
+
+		for (j = 0; j < cell_size; j++) {
+			uint32 address = j + cell_addr;
+
+			if (!sal_mem_is_address_valid(address)) {
+				continue;
+			}
+
+			inst_sum += sal_mem_get_inst(address);
+
+			if (sal_mem_is_allocated(address)) {
+				alloc_flag = ALLOCATED_FLAG;
+			}
+		}
+
+		buffer[i] = (uint8)(inst_sum / cell_size);
+		buffer[i] |= (uint8)(alloc_flag);
+	}
+
+	/* We also iterate through all processes and append extra bit flags to the
+	rendered image signaling process IP position and memory block limits.
+	*/
+	max_pos = origin + (cell_size * buff_size);
+
+	#pragma omp parallel for
+	for (i = 0; i < sal_proc_get_count(); i++) {
+		if (!sal_proc_is_free(i)) {
+			Process proc = sal_proc_get_proc(i);
+			apply_flag(origin, max_pos, cell_size, proc.ip, IP_FLAG, buffer);
+			apply_flag(
+				origin, max_pos, cell_size, proc.mb1a, BLOCK_FLAG, buffer
+			);
+
+			if (proc.mb2s) {
+				apply_flag(
+					origin, max_pos, cell_size, proc.mb2a, BLOCK_FLAG, buffer
+				);
+			}
+		}
+	}
+}
-- 
cgit v1.2.1