fix cpu llama 推理端到端精度

src/devices/cpu/common_cpu.cc

@@ -44,22 +44,19 @@ uint16_t f32_to_f16(float val) {
     int32_t exponent = ((f32 >> 23) & 0xFF) - 127;// Extract and de-bias the exponent
     uint32_t mantissa = f32 & 0x7FFFFF;           // Extract the mantissa (fraction part)
 
-    if (exponent == 128) {// Special case for Inf and NaN
-        if (mantissa != 0) {
-            // NaN
-            return sign | 0x7C00 | (mantissa >> 13);// Convert the NaN payload
-        } else {
-            // Infinity
-            return sign | 0x7C00;
+    if (exponent >= 31) {// Special cases for Inf and NaN
+        // NaN
+        if (exponent == 128 && mantissa != 0) {
+            return sign | 0x7E00;
         }
-    } else if (exponent > 15) {  // Overflow: Larger than float16 max
-        return sign | 0x7C00;    // Return infinity
-    } else if (exponent >= -14) {// Normalized float16
+        // Infinity
+        return sign | 0x7C00;
+    } else if (exponent >= -14) {// Normalized case
         return sign | ((exponent + 15) << 10) | (mantissa >> 13);
-    } else if (exponent >= -24) {     // Subnormal float16 (leading denormals)
-        mantissa |= 0x800000;         // Add implicit leading 1
-        int32_t shift = -exponent - 1;// Calculate shift for subnormal numbers
-        return sign | (mantissa >> (13 + shift));
+    } else if (exponent >= -24) {
+        mantissa |= 0x800000;// Add implicit leading 1
+        mantissa >>= (-14 - exponent);
+        return sign | (mantissa >> 13);
     } else {
         // Too small for subnormal: return signed zero
         return sign;

src/ops/matmul/cpu/matmul_cpu.cc

@@ -64,7 +64,11 @@ infiniopStatus_t matmul_cpu(MatmulCpuDescriptor_t desc, void *c, float beta, voi
                     }
                 }
                 if constexpr (std::is_same<Tdata, uint16_t>::value) {
-                    *c_ = f32_to_f16(beta * f16_to_f32(*c_) + alpha * sum);
+                    if (beta == 0) {
+                        *c_ = f32_to_f16(alpha * sum);
+                    } else {
+                        *c_ = f32_to_f16(beta * f16_to_f32(*c_) + alpha * sum);
+                    }
                 } else {
                     *c_ = beta * (*c_) + alpha * sum;
                 }