Use alloca for temp space decoding/encoding IMA4 blocks

CMakeLists.txt

@@ -314,6 +314,7 @@ CHECK_C_SOURCE_COMPILES("int foo(const char *str, ...) __attribute__((format(pri
                          int main() {return 0;}" HAVE_GCC_FORMAT)
 
 CHECK_INCLUDE_FILE(malloc.h HAVE_MALLOC_H)
+CHECK_INCLUDE_FILE(alloca.h HAVE_ALLOCA_H)
 CHECK_INCLUDE_FILE(strings.h HAVE_STRINGS_H)
 CHECK_INCLUDE_FILE(cpuid.h HAVE_CPUID_H)
 CHECK_INCLUDE_FILE(sys/sysconf.h HAVE_SYS_SYSCONF_H)
@@ -337,6 +338,19 @@ CHECK_SYMBOL_EXISTS(aligned_alloc    stdlib.h HAVE_ALIGNED_ALLOC)
 CHECK_SYMBOL_EXISTS(posix_memalign   stdlib.h HAVE_POSIX_MEMALIGN)
 CHECK_SYMBOL_EXISTS(_aligned_malloc  malloc.h HAVE__ALIGNED_MALLOC)
 CHECK_SYMBOL_EXISTS(lrintf math.h HAVE_LRINTF)
+IF(HAVE_ALLOCA_H)
+    CHECK_SYMBOL_EXISTS(alloca alloca.h HAVE_ALLOCA)
+ELSEIF(HAVE_MALLOC_H)
+    CHECK_SYMBOL_EXISTS(alloca malloc.h HAVE_ALLOCA)
+ENDIF()
+IF(NOT HAVE_ALLOCA)
+    CHECK_SYMBOL_EXISTS(_alloca malloc.h HAVE__ALLOCA)
+    IF(NOT HAVE__ALLOCA)
+        MESSAGE(FATAL_ERROR "No alloca function found, please report!")
+    ENDIF()
+
+    ADD_DEFINITIONS(-Dalloca=_alloca)
+ENDIF()
 
 IF(HAVE_FLOAT_H)
     CHECK_SYMBOL_EXISTS(_controlfp float.h HAVE__CONTROLFP)

OpenAL32/alBuffer.c

@@ -24,6 +24,12 @@
 #include <stdio.h>
 #include <assert.h>
 #include <limits.h>
+#ifdef HAVE_ALLOCA_H
+#include <alloca.h>
+#endif
+#ifdef HAVE_MALLOC_H
+#include <malloc.h>
+#endif
 
 #include "alMain.h"
 #include "alu.h"
@@ -1598,11 +1604,11 @@ DECL_TEMPLATE2(ALubyte3)
 static void Convert_##T##_ALima4(T *dst, const ALima4 *src, ALuint numchans,  \
                                  ALuint len)                                  \
 {                                                                             \
-    ALshort tmp[65*MAX_INPUT_CHANNELS]; /* Max samples an IMA4 frame can be */\
     ALuint i, j, k;                                                           \
+    ALshort *tmp;                                                             \
                                                                               \
-    i = 0;                                                                    \
-    while(i < len)                                                            \
+    tmp = alloca(65*numchans);                                                \
+    for(i = 0;i < len;)                                                       \
     {                                                                         \
         DecodeIMA4Block(tmp, src, numchans);                                  \
         src += 36*numchans;                                                   \
@@ -1634,11 +1640,12 @@ DECL_TEMPLATE(ALubyte3)
 static void Convert_ALima4_##T(ALima4 *dst, const T *src, ALuint numchans,    \
                                ALuint len)                                    \
 {                                                                             \
-    ALshort tmp[65*MAX_INPUT_CHANNELS]; /* Max samples an IMA4 frame can be */\
     ALint sample[MaxChannels] = {0,0,0,0,0,0,0,0};                            \
     ALint index[MaxChannels] = {0,0,0,0,0,0,0,0};                             \
+    ALshort *tmp;                                                             \
     ALuint i, j;                                                              \
                                                                               \
+    tmp = alloca(65*numchans);                                                \
     for(i = 0;i < len;i += 65)                                                \
     {                                                                         \
         for(j = 0;j < 65*numchans;j++)                                        \

config.h.in

@@ -116,6 +116,9 @@
 /* Define if we have malloc.h */
 #cmakedefine HAVE_MALLOC_H
 
+/* Define if we have alloca.h */
+#cmakedefine HAVE_ALLOCA_H
+
 /* Define if we have strings.h */
 #cmakedefine HAVE_STRINGS_H