metal : refactor mat-vec code (#12569)

* metal : refactor mat-vec code

ggml-ci

* metal : rename all_sum -> sum_all

ggml-ci

* metal : fix comments [no ci]

* metal : fix nr constant [no ci]

* metal : mv q6_K support nr0 > 1

ggml-ci

* metal : reduce register pressure

ggml-ci

* metal : fix typo [no ci]

* metal : reduce register pressure

ggml-ci

Author: ggerganov

ggml/src/ggml-metal/ggml-metal-impl.h

@@ -1,6 +1,70 @@
 #ifndef GGML_METAL_IMPL
 #define GGML_METAL_IMPL
 
+// kernel parameters for mat-vec threadgroups
+//
+// N_R0: number of src0 rows to process per simdgroup
+// N_SG: number of simdgroups per threadgroup
+//
+// TODO: for optimal performance, become function of the device and work size
+
+#define N_R0_Q4_0 4
+#define N_SG_Q4_0 2
+
+#define N_R0_Q4_1 4
+#define N_SG_Q4_1 2
+
+#define N_R0_Q5_0 4
+#define N_SG_Q5_0 2
+
+#define N_R0_Q5_1 4
+#define N_SG_Q5_1 2
+
+#define N_R0_Q8_0 4
+#define N_SG_Q8_0 2
+
+#define N_R0_Q2_K 4
+#define N_SG_Q2_K 2
+
+#define N_R0_Q3_K 2
+#define N_SG_Q3_K 2
+
+#define N_R0_Q4_K 4
+#define N_SG_Q4_K 2
+
+#define N_R0_Q5_K 2
+#define N_SG_Q5_K 2
+
+#define N_R0_Q6_K 1
+#define N_SG_Q6_K 2
+
+#define N_R0_IQ1_S 4
+#define N_SG_IQ1_S 2
+
+#define N_R0_IQ1_M 4
+#define N_SG_IQ1_M 2
+
+#define N_R0_IQ2_XXS 4
+#define N_SG_IQ2_XXS 2
+
+#define N_R0_IQ2_XS 4
+#define N_SG_IQ2_XS 2
+
+#define N_R0_IQ2_S 4
+#define N_SG_IQ2_S 2
+
+#define N_R0_IQ3_XXS 4
+#define N_SG_IQ3_XXS 2
+
+#define N_R0_IQ3_S 4
+#define N_SG_IQ3_S 2
+
+#define N_R0_IQ4_NL 2
+#define N_SG_IQ4_NL 2
+
+#define N_R0_IQ4_XS 2
+#define N_SG_IQ4_XS 2
+
 // kernel argument structs
 //
 // - element counters (e.g. ne00) typically use int32_t to reduce register usage