Opt

CMakeLists.txt

@@ -8,6 +8,7 @@ set(CMAKE_EXE_LINKER_FLAGS "-fsanitize=undefined -rdynamic")
 
 include_directories(.)
 include_directories(lexer)
+include_directories(optimize)
 include_directories(parser)
 include_directories(quads)
 include_directories(target_x86)
@@ -40,6 +41,8 @@ include_directories(${GENERATED})
 add_executable(dcc
 ${BISON_dcc_parser_OUTPUTS}
 ${FLEX_dcc_lexer_OUTPUTS}
+    optimize/opt_flatten_adjacent_mov.c
+    optimize/optimization.c
     parser/ast.c
     parser/ast_print.c
     parser/symtab.c

main.c

@@ -9,11 +9,12 @@
 #include <unistd.h>
 
 #include "asmgen.h"
+#include "optimization.h"
 #include "parser.tab.h"
 #include "quads.h"
 #include "util.h"
 
-#define DCC_VERSION "0.2.0"
+#define DCC_VERSION "0.2.0_opt"
 #define DCC_ARCHITECTURE "x86_32"
 
 #define BRED "\033[1;31m"
@@ -32,11 +33,15 @@ FILE* tmp;
 static struct opt {
     bool debug;
     bool asm_out;
+    bool optimize;
     const char* out_file;
     const char* in_file;
 } opt = {
+    .debug = false,
     .asm_out = false,
+    .optimize = false,
     .out_file = NULL,
+    .in_file = NULL
 };
 
 static void print_usage_additional() {
@@ -61,6 +66,7 @@ static void print_usage() {
         "\n   -h              show extended usage"
         "\n   -o output_file  specify output file"
         "\n   -S              output assembly only"
+        "\n   -O              enable optimization."
         "\n   -v              debug mode:"
         "\n                         -v: enable INFO messages"
         "\n                        -vv: enable VERBOSE messages"
@@ -74,7 +80,7 @@ static void print_usage() {
 static void get_options(int argc, char** argv) {
     int a;
     opterr = 0;
-    while ((a = getopt(argc, argv, "hvVSo:")) != -1) {
+    while ((a = getopt(argc, argv, "hvVSOo:")) != -1) {
         switch (a) {
             case 'h':
                 print_usage();
@@ -93,6 +99,9 @@ static void get_options(int argc, char** argv) {
             case 'S':
                 opt.asm_out = true;
                 break;
+            case 'O':
+                opt.optimize = true;
+                break;
             case 'o':
                 opt.out_file = optarg;
                 break;
@@ -207,6 +216,10 @@ int main(int argc, char** argv) {
     fclose(tmp);
 }
 
-void parse_done_cb(const BBL* root) {
+void parse_done_cb(BBL* root) {
+    if (opt.optimize) {
+        // optimization passes
+        dcc_optimize(root);
+    }
     asmgen(root, tmp);
 }

main.h

@@ -1,6 +1,6 @@
 #ifndef MAIN_H
 #define MAIN_H
 
-void parse_done_cb(const BBL* root);
+void parse_done_cb(BBL* root);
 
 #endif

optimize/opt_flatten_adjacent_mov.c

@@ -0,0 +1,78 @@
+#include "opt_flatten_adjacent_mov.h"
+
+#include <stdlib.h>
+
+#include "quads.h"
+#include "quads_cf.h"
+
+unsigned total_replaced = 0;
+
+void try_replace_temp(astn* n, struct astn_qtemp* del, struct astn_qtemp* replace) {
+    if (n && n->type == ASTN_QTEMP && n->Qtemp.tempno == del->tempno)
+        n->Qtemp = *replace;
+
+    total_replaced++;
+}
+
+void opt_flatten_adjacent_mov(BBL* root, unsigned passes) {
+    BBL* head = root;
+    unsigned hits = 0;
+    for (unsigned pass = 1; pass <= passes; pass++) {
+        // fprintf(stderr, "Pass %d/%d running...\n", pass, passes);
+        unsigned this_hits = 0, quads_visited = 0;
+        BBL* bbl = head;
+        if (head == &bb_root) bbl = bbl_next(bbl);
+
+        while (bbl) {
+            BB* b = bbl_data(bbl);
+            bbl = bbl_next(bbl);
+            quad *q = b->start;
+
+            while (q && q->next && q->next->next) {
+                quads_visited++;
+                quad *n = q->next;
+                quad *nn = n->next;
+                if ((q->op == Q_MOV && n->op == Q_MOV) &&
+                    (q->target->type == ASTN_SYMPTR && q->src1->type == ASTN_QTEMP) &&
+                    (n->target->type == ASTN_QTEMP && n->src1->type == ASTN_SYMPTR) &&
+                    (q->target->Symptr.e == n->src1->Symptr.e)) {
+                        this_hits++;
+                        // we found the pattern.
+                        // now we will remove the second quad entirely
+                        // and replace all references to its target with the parent's source.
+                        struct astn_qtemp* del = &n->target->Qtemp;
+                        struct astn_qtemp* replace = &q->src1->Qtemp;
+                        //fprintf(stderr, "del is %u, replace is %u\n", del->tempno, replace->tempno);
+
+                        q->next = nn;
+                        free(n); // todo: potentially still leaky?
+
+                        while (nn) {
+                            try_replace_temp(nn->target, del, replace);
+                            try_replace_temp(nn->src1, del, replace);
+                            try_replace_temp(nn->src2, del, replace);
+                            nn = nn->next;
+                        }
+                }
+                q = q->next;
+            }
+        }
+        hits += this_hits;
+        // fprintf(stderr, "--> Quads visited: %d | hits for this pass: %d, all passes: %d\n", quads_visited, this_hits, hits);
+    }
+    BBL* bbl = head;
+    if (head == &bb_root) bbl = bbl_next(bbl);
+
+
+    unsigned remaining_quads = 0;
+    while (bbl) {
+        BB* b = bbl_data(bbl);
+        bbl = bbl_next(bbl);
+        quad *q = b->start;
+        while (q) {
+            q = q->next;
+            remaining_quads++;
+        }
+    }
+    // fprintf(stderr, "Remaining quads after optimization: %d\n", remaining_quads);
+}

optimize/opt_flatten_adjacent_mov.h

@@ -0,0 +1,8 @@
+#ifndef OPT_FLATTEN_ADJACENT_MOV_H
+#define OPT_FLATTEN_ADJACENT_MOV_H
+
+#include "quads_cf.h"
+
+void opt_flatten_adjacent_mov(BBL* root, unsigned passes);
+
+#endif

optimize/optimization.c

@@ -0,0 +1,7 @@
+#include "optimization.h"
+
+#include "opt_flatten_adjacent_mov.h"
+
+void dcc_optimize(BBL* head) {
+    opt_flatten_adjacent_mov(head, 1);
+}

optimize/optimization.h

@@ -0,0 +1,8 @@
+#ifndef OPTIMIZATION_H
+#define OPTIMIZATION_H
+
+#include "quads_cf.h"
+
+void dcc_optimize(BBL* head);
+
+#endif

target_x86/asmgen.c

@@ -9,6 +9,8 @@
 #include "types.h"
 #include "util.h"
 
+#include "opt_flatten_adjacent_mov.h"
+
 #include <stdio.h>
 
 FILE* out;
@@ -239,7 +241,7 @@ void e_cbr(const char *op, quad* q) {
 void e_bba(const astn *n) { e_bb(n->Qbbno.bb); }
 void e_bb(const BB* b) { fprintf(out, "BB.%s.%d", b->fn, b->bbno); }
 
-void asmgen(const BBL* head, FILE* f) {
+void asmgen(BBL* head, FILE* f) {
     // init output file
     out = f;
     fprintf(out, "# ASM OUTPUT\n# compiled poorly :)\n\n");

target_x86/asmgen.h

@@ -22,6 +22,6 @@ typedef struct adir {
 void e_cbr(const char *op, quad* q);
 void e_bba(const astn *n);
 void e_bb(const BB* b);
-void asmgen(const BBL* bbl, FILE* out);
+void asmgen(BBL* bbl, FILE* out);
 
 #endif