COMPMID-3776: Indirect GEMM

Signed-off-by: Georgios Pinitas <georgios.pinitas@arm.com>
Change-Id: I51a1b0f098bc3a8c408c50c92221e4df3061e12c
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/4343
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Sang-Hoon Park <sang-hoon.park@arm.com>
Reviewed-by: Michele Di Giorgio <michele.digiorgio@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>

1 files changed, 12 insertions, 3 deletions

diff --git a/src/core/NEON/kernels/arm_gemm/gemm_hybrid_quantized.hpp b/src/core/NEON/kernels/arm_gemm/gemm_hybrid_quantized.hpp
index 915227fc29..7a5fa87ee6 100644
--- a/src/core/NEON/kernels/arm_gemm/gemm_hybrid_quantized.hpp
+++ b/src/core/NEON/kernels/arm_gemm/gemm_hybrid_quantized.hpp
@@ -118,18 +118,27 @@ class GemmHybridQuantized : public GemmCommon<To, Tr> {
 
         // n_block: Work out how many rows (of length k_block) will fit in the L2
         // Don't allocate more than 90% of the L2 to allow for overheads, and subtract off the L1 contents.
-        unsigned int n_block = (((L2_size * 9) / 10) - (k_block * sizeof(Toi) * (strategy::out_width() + strategy::out_height()))) /
-                                 (sizeof(Toi) * k_block);
+        const unsigned int scaled_l2_size = (L2_size * 9) / 10;
+        const unsigned int k_block_area = k_block * sizeof(Toi) * (strategy::out_width() + strategy::out_height());
+
+        // .. if the L1 contents is bigger than the L2, just return a minimal size block.
+        if (k_block_area > scaled_l2_size) {
+            return strategy::out_width();
+        }
+
+        unsigned int n_block = (scaled_l2_size - k_block_area) / (sizeof(Toi) * k_block);
 
         // Needs to be (at least a single) multiple of the kernel output width.
         n_block /= strategy::out_width();
-        n_block = std::max(n_block, 1U) * strategy::out_width();
+        n_block = std::max(n_block, 1u) * strategy::out_width();
 
         // And tune to the presented problem size.
         unsigned int numblocks = iceildiv(args._Nsize, n_block);
         n_block = iceildiv(args._Nsize, numblocks);
         n_block = roundup(n_block, strategy::out_width());
 
+        assert(n_block > 0);
+
         return n_block;
     }