From f92c5b96acb7057b1acbae6447de850ede1c094e Mon Sep 17 00:00:00 2001
From: "X.organic" <dilithium.no3@protonmail.com>
Date: Mon, 22 Aug 2022 13:25:24 +0200
Subject: [PATCH] Fix a performance regression in query functions
This commit brings back the old code for W_CheckNumForNamePwad, using memcmp
instead of strncmp, which is readily inlined by modern C compilers and has
more acceptable performance in P_AddWadFile. Also removes some redundant
strlens, saving the result of one call instead.
This commit increases this branch's distance from SRB2 2.2, per Ashnal
and SteelT's note that I shouldn't worry too much about it, especially
when there's performance on the line.
---
src/w_wad.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/src/w_wad.c b/src/w_wad.c
index ce47b849d..3f6d0fd15 100644
--- a/src/w_wad.c
+++ b/src/w_wad.c
@@ -953,7 +953,8 @@ UINT16 W_CheckNumForNamePwad(const char *name, UINT16 wad, UINT16 startlump)
if (!TestValidLump(wad,0))
return INT16_MAX;
- strlcpy(uname, name, sizeof uname);
+ memset(uname, 0, sizeof uname);
+ strncpy(uname, name, sizeof(uname)-1);
strupr(uname);
//
@@ -965,7 +966,7 @@ UINT16 W_CheckNumForNamePwad(const char *name, UINT16 wad, UINT16 startlump)
{
lumpinfo_t *lump_p = wadfiles[wad]->lumpinfo + startlump;
for (i = startlump; i < wadfiles[wad]->numlumps; i++, lump_p++)
- if (!strncmp(lump_p->name, uname, sizeof(uname) - 1))
+ if (memcmp(lump_p->name, uname, sizeof(uname) - 1) == 0)
return i;
}
@@ -1044,9 +1045,10 @@ UINT16 W_CheckNumForFolderEndPK3(const char *name, UINT16 wad, UINT16 startlump)
{
INT32 i;
lumpinfo_t *lump_p = wadfiles[wad]->lumpinfo + startlump;
+ size_t name_length = strlen(name);
for (i = startlump; i < wadfiles[wad]->numlumps; i++, lump_p++)
{
- if (strnicmp(name, lump_p->fullname, strlen(name)))
+ if (strnicmp(name, lump_p->fullname, name_length))
break;
}
return i;
@@ -1058,9 +1060,10 @@ UINT16 W_CheckNumForFullNamePK3(const char *name, UINT16 wad, UINT16 startlump)
{
INT32 i;
lumpinfo_t *lump_p = wadfiles[wad]->lumpinfo + startlump;
+ size_t name_length = strlen(name);
for (i = startlump; i < wadfiles[wad]->numlumps; i++, lump_p++)
{
- if (!strnicmp(name, lump_p->fullname, strlen(name)))
+ if (!strnicmp(name, lump_p->fullname, name_length))
{
return i;
}
--
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