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| author | Bertrand Augereau | 2011-07-25 13:24:03 +0200 |
|---|---|---|
| committer | Johannes Schickel | 2011-08-19 01:05:37 +0200 |
| commit | ff98725172cd1b57251fb9ead4ef1aaf4081e730 (patch) | |
| tree | a4de7dbc8bacd20a64ba0c393f7e797ed3a290d5 | |
| parent | dd0ad3cba4534cb9b36dc0b6c8b412a0f1b10cf2 (diff) | |
| download | scummvm-rg350-ff98725172cd1b57251fb9ead4ef1aaf4081e730.tar.gz scummvm-rg350-ff98725172cd1b57251fb9ead4ef1aaf4081e730.tar.bz2 scummvm-rg350-ff98725172cd1b57251fb9ead4ef1aaf4081e730.zip | |
COMMON: intLog2 uses _BitScanReverse on MSVC
| -rw-r--r-- | base/main.cpp | 1 | ||||
| -rw-r--r-- | common/math.h | 33 |
2 files changed, 34 insertions, 0 deletions
diff --git a/base/main.cpp b/base/main.cpp index a0792a9ad2..435eeb1571 100644 --- a/base/main.cpp +++ b/base/main.cpp @@ -48,6 +48,7 @@ #include "common/textconsole.h" #include "common/tokenizer.h" #include "common/translation.h" +#include "common/math.h" #include "gui/gui-manager.h" #include "gui/error.h" diff --git a/common/math.h b/common/math.h index 56ab171bd3..f787b84fa6 100644 --- a/common/math.h +++ b/common/math.h @@ -26,6 +26,31 @@ #define COMMON_MATH_H #include "common/scummsys.h" +#ifdef _MSC_VER +// HACK: +// intrin.h on MSVC includes setjmp.h, which will fail compiling due to our +// forbidden symbol colde. Since we also can not assure that defining +// FORBIDDEN_SYMBOL_EXCEPTION_setjmp and FORBIDDEN_SYMBOL_EXCEPTION_longjmp +// will actually allow the symbols, since forbidden.h might be included +// earlier already we need to undefine them here... +#undef setjmp +#undef longjmp +#include <intrin.h> +// ...and redefine them here so no code can actually use it. +// This could be resolved by including intrin.h on MSVC in scummsys.h before +// the forbidden.h include. This might make sense, in case we use MSVC +// extensions like _BitScanReverse in more places. But for now this hack should +// be ok... +#ifndef FORBIDDEN_SYMBOL_EXCEPTION_setjmp +#undef setjmp +#define setjmp(a) FORBIDDEN_SYMBOL_REPLACEMENT +#endif + +#ifndef FORBIDDEN_SYMBOL_EXCEPTION_longjmp +#undef longjmp +#define longjmp(a,b) FORBIDDEN_SYMBOL_REPLACEMENT +#endif +#endif #ifndef M_SQRT1_2 #define M_SQRT1_2 0.70710678118654752440 /* 1/sqrt(2) */ @@ -63,6 +88,14 @@ inline int intLog2(uint32 v) { // limits.h return (sizeof(unsigned int) * 8 - 1) - __builtin_clz(v); } +#elif defined(_MSC_VER) +inline int intLog2(uint32 v) { + unsigned long result = 0; + unsigned char nonZero = _BitScanReverse(&result, v); + // _BitScanReverse stores the position of the MSB set in case its result + // is non zero, thus we can just return it as is. + return nonZero ? result : -1; +} #else // See http://graphics.stanford.edu/~seander/bithacks.html#IntegerLogLookup static const char LogTable256[256] = { |