Update optimizer.c

An optimized version of SIMD is used in file cpython/Python/optimizer.c for function count_exits().

Author: IvanovVj

Python/optimizer.c

@@ -17,6 +17,10 @@
 #include <stdint.h>
 #include <stddef.h>
 
+#ifdef USE_SIMD                    // HACL_CAN_COMPILE_VEC256
+#include <immintrin.h>
+#endif
+
 #define NEED_OPCODE_METADATA
 #include "pycore_uop_metadata.h" // Uop tables
 #undef NEED_OPCODE_METADATA
@@ -307,7 +311,7 @@ static int
 executor_traverse(PyObject *o, visitproc visit, void *arg)
 {
     _PyExecutorObject *executor = (_PyExecutorObject *)o;
-    for (uint32_t i = 0; i < executor->exit_count; i++) {
+    for (uint32_t i = 0; i < executor->; i++) {
         Py_VISIT(executor->exits[i].executor);
     }
     return 0;
@@ -923,17 +927,53 @@ translate_bytecode_to_trace(
 #define BIT_IS_SET(array, bit) (array[(bit)>>5] & (1<<((bit)&31)))
 
 /* Count the number of unused uops and exits
+* An optimized version of SIMD is used.
 */
 static int
 count_exits(_PyUOpInstruction *buffer, int length)
 {
     int exit_count = 0;
+#if defined(USE_SIMD)
+    // Use SIMD instructions for optimization of counting
+    // Assume that _PyUOpInstruction contains only opcode
+    // and its size is a multiple of the SIMD register size
+    
+    // For AVX2 (256-bit registers)
+    const __m256i exit_code = _mm256_set1_epi32(_EXIT_TRACE);
+    const __m256i zero = _mm256_setzero_si256();
+    
+    int i;
+
+    // Process data in blocks of 8 elements (256 bits / 32 bits)
+    for (i = 0; i < length - 7; i += 8) {
+        __m256i vec = _mm256_load_si256((const __m256i*)(buffer + i));
+        __m256i cmp = _mm256_cmpeq_epi32(vec, exit_code);
+        __m256i sum = _mm256_add_epi32(cmp, zero);
+        
+        // Sum horizontal values
+        __m128i lo = _mm256_extracti128_si256(sum, 0);
+        __m128i hi = _mm256_extracti128_si256(sum, 1);
+        __m128i total = _mm_add_epi32(lo, hi);
+        
+        int result;
+        _mm_store_si128((__m128i*)&result, total);
+        exit_count += _mm_extract_epi32(total, 0) + _mm_extract_epi32(total, 1);
+    }
+    
+    // Process remaining elements
+    for (; i < length; i++) {
+        if (buffer[i].opcode == _EXIT_TRACE) {
+            exit_count++;
+        }
+    }
+#else
     for (int i = 0; i < length; i++) {
         int opcode = buffer[i].opcode;
         if (opcode == _EXIT_TRACE) {
             exit_count++;
         }
     }
+#endif
     return exit_count;
 }