cuda : fix __hisinf() result check

Author: ggerganov

ggml-cuda.cu

@@ -6597,8 +6597,8 @@ static __global__ void flash_attn_ext_f16(
                     smax = warp_reduce_max(__hmax(smax, s));
                     M[j] = warp_reduce_max(__hmax(M[j], s));
 
-                    const half ms = __hisinf(m) ? __float2half(0.0f) : hexp(m - M[j]);
-                    const half vs = __hisinf(s) ? __float2half(0.0f) : hexp(s - M[j]);
+                    const half ms = __hisinf(m) == -1 ? __float2half(0.0f) : hexp(m - M[j]);
+                    const half vs = __hisinf(s) == -1 ? __float2half(0.0f) : hexp(s - M[j]);
 
                     S[j] = S[j]*ms + warp_reduce_sum(vs);
 
@@ -6624,7 +6624,7 @@ static __global__ void flash_attn_ext_f16(
                     smax = warp_reduce_max(smax);
                     M[j] = warp_reduce_max(M[j]);
 
-                    const half ms = __hisinf(m) ? __float2half(0.0f) : hexp(m - M[j]);
+                    const half ms = __hisinf(m) == -1 ? __float2half(0.0f) : hexp(m - M[j]);
 
                     // create a QxQ diagonal matrix for rescaling the output
                     if (lane_id == j) {
@@ -6637,7 +6637,7 @@ static __global__ void flash_attn_ext_f16(
                     for (int64_t p = lane_id; p < C; p += NW) {
                         const half s = ss[j*T + p];
 
-                        const half vs = __hisinf(s) ? __float2half(0.0f) : hexp(s - M[j]);
+                        const half vs = __hisinf(s) == -1 ? __float2half(0.0f) : hexp(s - M[j]);
 
                         ls += vs;
 
@@ -6650,7 +6650,7 @@ static __global__ void flash_attn_ext_f16(
             }
 
             // skip -INF blocks
-            if (__hisinf(smax)) {
+            if (__hisinf(smax) == -1) {
                 continue;
             }
 
@@ -6735,8 +6735,8 @@ static __global__ void flash_attn_ext_f16(
 
                 M = __hmax(M0, M1);
 
-                const half ms0 = __hisinf(M0) ? __float2half(0.0f) : hexp(M0 - M);
-                const half ms1 = __hisinf(M1) ? __float2half(0.0f) : hexp(M1 - M);
+                const half ms0 = __hisinf(M0) == -1 ? __float2half(0.0f) : hexp(M0 - M);
+                const half ms1 = __hisinf(M1) == -1 ? __float2half(0.0f) : hexp(M1 - M);
 
                 S = S0*ms0 + S1*ms1;