Revert "pngpriv: Enable SSE opt based on compiler support"

This reverts commit ae304f5.
pnggroup · Aug 12, 2024 · 24a7005 · 24a7005
1 parent 5499c55
commit 24a7005
Showing 1 changed file with 12 additions and 4 deletions.
diff --git a/pngpriv.h b/pngpriv.h
@@ -187,10 +187,18 @@
 #endif
 
 #ifndef PNG_INTEL_SSE_OPT
-#   if defined(__SSE4_1__) || defined(__AVX__) || defined(__SSSE3__) || \
-    defined(__SSE2__) || defined(_M_X64) || defined(_M_AMD64) || \
-    (defined(_M_IX86_FP) && _M_IX86_FP >= 2)
-#      define PNG_INTEL_SSE_OPT 1
+#   ifdef PNG_INTEL_SSE
+      /* Only check for SSE if the build configuration has been modified to
+       * enable SSE optimizations.  This means that these optimizations will
+       * be off by default.  See contrib/intel for more details.
+       */
+#      if defined(__SSE4_1__) || defined(__AVX__) || defined(__SSSE3__) || \
+       defined(__SSE2__) || defined(_M_X64) || defined(_M_AMD64) || \
+       (defined(_M_IX86_FP) && _M_IX86_FP >= 2)
+#         define PNG_INTEL_SSE_OPT 1
+#      else
+#         define PNG_INTEL_SSE_OPT 0
+#      endif
 #   else
 #      define PNG_INTEL_SSE_OPT 0
 #   endif