Don't use stack to save rbx register

diff --git a/src/pcm/pcm_dmix_x86_64.h b/src/pcm/pcm_dmix_x86_64.h
index cbcb2cb4676f5592e5ffcb1e2194c28425fd9994..973ed3f9fe099180ca942549a68c2131362d6bc0 100644 (file)
--- a/src/pcm/pcm_dmix_x86_64.h
+++ b/src/pcm/pcm_dmix_x86_64.h
@@ -35,10 +35,12 @@ static void MIX_AREAS1(unsigned int size,
                       volatile signed int *sum, size_t dst_step,
                       size_t src_step, size_t sum_step)
 {
+       unsigned long long old_rbx;
+
        /*
-        *  ESI - src
-        *  EDI - dst
-        *  EBX - sum
+        *  RSI - src
+        *  RDI - dst
+        *  RBX - sum
         *  ECX - old sample
         *  EAX - sample / temporary
         *  EDX - temporary
@@ -46,9 +48,9 @@ static void MIX_AREAS1(unsigned int size,
        __asm__ __volatile__ (
                "\n"
 
-               "\tpush %%rbx\n"
+               "\tmovq %%rbx, %7\n"
                /*
-                *  initialization, load ESI, EDI, EBX registers
+                *  initialization, load RSI, RDI, RBX registers
                 */
                "\tmovq %1, %%rdi\n"
                "\tmovq %2, %%rsi\n"
@@ -106,16 +108,17 @@ static void MIX_AREAS1(unsigned int size,
                "\tadd %6, %%rbx\n"
                "\tdecl %0\n"
                "\tjnz 1b\n"
-               "\tjmp 6f\n"
 
                "6:"
                
                "\temms\n"
-               "\tpop %%rbx\n"
+               "\tmovq %7, %%rbx\n"
 
                : /* no output regs */
-               : "m" (size), "m" (dst), "m" (src), "m" (sum), "m" (dst_step), "m" (src_step), "m" (sum_step)
-               : "rsi", "rdi", "edx", "ecx", "rbx", "eax"
+               : "m" (size), "m" (dst), "m" (src),
+                 "m" (sum), "m" (dst_step), "m" (src_step),
+                 "m" (sum_step), "m" (old_rbx)
+               : "rsi", "rdi", "edx", "ecx", "eax"
        );
 }
 
@@ -127,10 +130,12 @@ static void MIX_AREAS2(unsigned int size,
                       volatile signed int *sum, size_t dst_step,
                       size_t src_step, size_t sum_step)
 {
+       unsigned long long old_rbx;
+
        /*
-        *  ESI - src
-        *  EDI - dst
-        *  EBX - sum
+        *  RSI - src
+        *  RDI - dst
+        *  RBX - sum
         *  ECX - old sample
         *  EAX - sample / temporary
         *  EDX - temporary
@@ -138,7 +143,7 @@ static void MIX_AREAS2(unsigned int size,
        __asm__ __volatile__ (
                "\n"
 
-               "\tpush %%rbx\n"
+               "\tmovq %%rbx, %7\n"
                /*
                 *  initialization, load ESI, EDI, EBX registers
                 */
@@ -220,14 +225,15 @@ static void MIX_AREAS2(unsigned int size,
                "\tadd %6, %%rbx\n"
                "\tdecl %0\n"
                "\tjnz 1b\n"
-               // "\tjmp 6f\n"
                
                "6:"
-               "\tpop %%rbx\n"
+               "\tmovq %7, %%rbx\n"
 
                : /* no output regs */
-               : "m" (size), "m" (dst), "m" (src), "m" (sum), "m" (dst_step), "m" (src_step), "m" (sum_step)
-               : "rsi", "rdi", "edx", "ecx", "rbx", "eax"
+               : "m" (size), "m" (dst), "m" (src),
+                 "m" (sum), "m" (dst_step), "m" (src_step),
+                 "m" (sum_step), "m" (old_rbx)
+               : "rsi", "rdi", "edx", "ecx", "eax"
        );
 }