Merge branch 'fix-percent-check' of https://github.com/d26435/stb into working

ago%!(EXTRA string=8 years) · 80a39f958f
parent 7bb64aa867 4338a0e55e
commit 80a39f958f
1 changed files with 4 additions and 1 deletions
--- a/stb_sprintf.h
+++ b/stb_sprintf.h
@ -247,9 +247,12 @@ STBSP__PUBLICDEF int STB_SPRINTF_DECORATE( vsprintfcb )( STBSP_SPRINTFCB * callb
      } 
      for(;;)
      { 
+        // Check if the next 4 bytes contain %(0x25) or end of string.
+        // Using the 'hasless' trick:
+        // https://graphics.stanford.edu/~seander/bithacks.html#HasLessInWord
        stbsp__uint32 v,c;
        v=*(stbsp__uint32*)f; c=(~v)&0x80808080;
-        if ((v-0x26262626)&c) goto schk1; 
+        if (((v^0x25252525)-0x01010101)&c) goto schk1;
        if ((v-0x01010101)&c) goto schk2; 
        if (callback) if ((STB_SPRINTF_MIN-(int)(bf-buf))<4) goto schk1;
        *(stbsp__uint32*)bf=v; bf+=4; f+=4;