Disable use of the i386 assembly for option -O0
We don't compile in the assembly code if compiler optimisations are disabled as
the number of registers used in the assembly code doesn't work with the -O0
option. Also anyone select -O0 probably doesn't want to compile in the assembly
code anyway.
diff --git a/include/mbedtls/bn_mul.h b/include/mbedtls/bn_mul.h
index e049260..438aa8c 100644
--- a/include/mbedtls/bn_mul.h
+++ b/include/mbedtls/bn_mul.h
@@ -49,7 +49,14 @@
/* armcc5 --gnu defines __GNUC__ but doesn't support GNU's extended asm */
#if defined(__GNUC__) && \
( !defined(__ARMCC_VERSION) || __ARMCC_VERSION >= 6000000 )
-#if defined(__i386__)
+
+/*
+ * Disable use of the i386 assembly code below if option -O0, to disable all
+ * compiler optimisations, is passed, detected with __OPTIMIZE__
+ * This is done as the number of registers used in the assembly code doesn't
+ * work with the -O0 option.
+ */
+#if defined(__i386__) && !defined(__OPTIMIZE__)
#define MULADDC_INIT \
asm( \
