From 5e46b36476c57418c0bd3cfced2d4c63eb7d1048 Mon Sep 17 00:00:00 2001
From: lemon <lsof@mailbox.org>
Date: Wed, 31 May 2023 08:57:22 +0200
Subject: '!' optimizations

---
 lex.c   | 11 +++++++----
 parse.c | 22 ++++++++++++++++++++--
 test.c  | 12 ++++++++++++
 3 files changed, 39 insertions(+), 6 deletions(-)

diff --git a/lex.c b/lex.c
index f82f255..a41bd0d 100644
--- a/lex.c
+++ b/lex.c
@@ -376,10 +376,13 @@ Begin:
    case ' ': case '\r': case '\t':
       goto Begin;
       break;
-   case '!': case '(': case ')': case ',':
-   case ':': case ';': case '?': case '[':
-   case ']': case '{': case '}': case '~':
-   case '$': case '@': case '`': case '\\': case TKEOF: case '\n':
+   case '(': case ')': case ',': case ':':
+   case ';': case '?': case '[': case ']':
+   case '{': case '}': case '~': case '$':
+   case '@': case '`': case '\\': case TKEOF: case '\n':
+      RET(c);
+   case '!':
+      if (match(pr, '=')) RET(TKNEQ);
       RET(c);
    case '#':
       if (match(pr, '#')) RET(TKPPCAT);
diff --git a/parse.c b/parse.c
index 16293f9..d3a5f99 100644
--- a/parse.c
+++ b/parse.c
@@ -1149,6 +1149,19 @@ Loop:
       condjump(fn, &ex->sub[1], tr, fl);
       useblk(fn, next2);
       condjump(fn, &ex->sub[2], tr, fl);
+   } else if (ex->t == ELOGNOT) {
+   Negate:
+      /* swap tr,fl */
+      next = tr;
+      tr = fl;
+      fl = next;
+      ex = &ex->sub[0];
+      goto Loop;
+   } else if (ex->t == EEQU && isnullpo(&ex->sub[1])) { /* == 0 */
+      goto Negate;
+   } else if (ex->t == ENEQ && isnullpo(&ex->sub[1])) { /* != 0 */
+      ex = &ex->sub[0];
+      goto Loop;
    } else {
       putjump(fn, Jbcnd, exprvalue(fn, ex), tr, fl);
    }
@@ -1204,7 +1217,10 @@ condexprrec(struct function *fn, const struct expr *ex, bool tobool,
 static union ref
 condexprvalue(struct function *fn, const struct expr *ex)
 {
-   struct condphis phis = {0};
+   struct block *blkbuf[8];
+   union ref refbuf[8];
+   struct condphis phis = { VINIT(blkbuf, arraylength(blkbuf)),
+                            VINIT(refbuf, arraylength(refbuf))};
    struct block *dst = newblk(fn);
    union ref r;
    condexprrec(fn, ex, 0, &phis, dst, NULL);
@@ -1258,7 +1274,9 @@ exprvalue(struct function *fn, const struct expr *ex)
       ins.cls = cls;
       return addinstr(fn, ins);
    case ELOGNOT:
-      ins.op = Oequ;
+      for (; sub->t == ELOGNOT; ex = sub, sub = sub->sub)
+         swp ^= 1;
+      ins.op = Oequ + swp;
       ins.l = exprvalue(fn, sub);
       ins.l = cvt(fn, ex->ty.t, sub->ty.t, ins.l);
       ins.r = mkintcon(fn, cls, 0);
diff --git a/test.c b/test.c
index e16e415..5adb14f 100644
--- a/test.c
+++ b/test.c
@@ -7,6 +7,8 @@ wawa
 #else
 boop
 #endif
+
+#define NULL ((void *)0)
 int glob [ wow+wow];
 
 struct foo {
@@ -32,4 +34,14 @@ int test4(int c) {
          : 0;
 }
 
+int test5(int *p)
+{
+    return p ? *p : 0;
+}
+
+int test6(int x)
+{
+    return !!!!x;
+}
+
 //
-- 
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