[nasm:rebin] RAA: add function to compare if two RAAs are identical

[nasm-bot for H. Peter Anvin]

Commit-ID:  cb3ed55e381ada421e43593bf91fafc546625a03
Gitweb:     http://repo.or.cz/w/nasm.git?a=commitdiff;h=cb3ed55e381ada421e43593bf91fafc546625a03
Author:     H. Peter Anvin <hpa at zytor.com>
AuthorDate: Mon, 21 Nov 2022 10:52:32 -0800
Committer:  H. Peter Anvin <hpa at zytor.com>
CommitDate: Mon, 21 Nov 2022 10:52:32 -0800

RAA: add function to compare if two RAAs are identical

Add raa_equal() to compare two RAAs, accounting for the fact that any
not-present entries in an RAA is zero.

Signed-off-by: H. Peter Anvin <hpa at zytor.com>


---
 include/nasmlib.h | 10 ++++++++-
 nasmlib/raa.c     | 62 ++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 70 insertions(+), 2 deletions(-)

diff --git a/include/nasmlib.h b/include/nasmlib.h
index 87a7fc6f..78d81f5d 100644
--- a/include/nasmlib.h
+++ b/include/nasmlib.h
@@ -1,6 +1,6 @@
 /* ----------------------------------------------------------------------- *
  *
- *   Copyright 1996-2020 The NASM Authors - All Rights Reserved
+ *   Copyright 1996-2022 The NASM Authors - All Rights Reserved
  *   See the file AUTHORS included with the NASM distribution for
  *   the specific copyright holders.
  *
@@ -54,6 +54,14 @@ union intorptr {
 };
 typedef union intorptr intorptr;
 
+static inline bool intorptr_bool(intorptr iop)
+{
+    if (sizeof(int64_t) >= sizeof(void *))
+        return !!iop.i;
+    else
+        return !!iop.p;
+}
+
 /*
  * Wrappers around malloc, realloc, free and a few more. nasm_malloc
  * will fatal-error and die rather than return NULL; nasm_realloc will
diff --git a/nasmlib/raa.c b/nasmlib/raa.c
index 038f97ac..4a0a4d9e 100644
--- a/nasmlib/raa.c
+++ b/nasmlib/raa.c
@@ -1,6 +1,6 @@
 /* ----------------------------------------------------------------------- *
  *
- *   Copyright 1996-2018 The NASM Authors - All Rights Reserved
+ *   Copyright 1996-2022 The NASM Authors - All Rights Reserved
  *   See the file AUTHORS included with the NASM distribution for
  *   the specific copyright holders.
  *
@@ -196,3 +196,63 @@ struct RAA *raa_write_ptr(struct RAA *r, raaindex posn, void *value)
     ip.p = value;
     return real_raa_write(r, posn, ip);
 }
+
+/* Test to see if an entire RAA (level) is all zero */
+static bool raa_is_zero(const struct RAA *top)
+{
+    size_t i;
+
+    if (!top)
+        return true;
+
+    if (!top->layers) {
+        for (i = 0; i < RAA_LAYERSIZE; i++) {
+            if (intorptr_bool(top->u.l.data[i]))
+                return false;
+        }
+    } else {
+        for (i = 0; i < RAA_LAYERSIZE; i++) {
+            if (!raa_is_zero(top->u.b.data[i]))
+                return false;
+        }
+    }
+    return true;
+}
+
+/* Return true if and only if both RAAs (which may be NULL) are identical */
+bool raa_equal(const struct RAA *r1, const struct RAA *r2)
+{
+    size_t i;
+
+    if (!r1)
+        return raa_is_zero(r2);
+    if (!r2)
+        return raa_is_zero(r1);
+
+    if (r1->layers < r2->layers) {
+        /* Swap so r1 is the "larger" RAA if necessary */
+        const struct RAA *rtmp = r2;
+        r2 = r1;
+        r1 = rtmp;
+    }
+
+    while (r1->layers > r2->layers) {
+        for (i = 1; i < RAA_LAYERSIZE; i++) {
+            if (!raa_is_zero(r1->u.b.data[i]))
+                return false;
+        }
+        r1 = r1->u.b.data[0];
+        if (!r1)
+            return raa_is_zero(r2);
+    }
+
+    if (!r1->layers) {
+        return !memcmp(&r1->u.l, &r2->u.l, sizeof r1->u.l);
+    } else {
+        for (i = 0; i < RAA_LAYERSIZE; i++) {
+            if (!raa_equal(r1->u.b.data[i], r2->u.b.data[i]))
+                return false;
+        }
+        return true;
+    }
+}