Bugfix for dequantizing q5k layers. (#1569)

huggingface · Jan 11, 2024 · 4191518 · 4191518
1 parent c1876b8
commit 4191518
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Showing 2 changed files with 5 additions and 5 deletions.
diff --git a/candle-core/src/quantized/k_quants.rs b/candle-core/src/quantized/k_quants.rs
@@ -1545,13 +1545,13 @@ impl GgmlType for BlockQ5K {
                 let d2 = d * sc as f32;
                 let m2 = min * m as f32;
                 for (ql, qh) in ql.iter().zip(qh) {
-                    let to_add = if qh & u1 != 0 { 16 } else { 1 };
-                    y[ys_index] = d1 * ((ql & 0xF) + to_add) as f32 - m1;
+                    let to_add = if qh & u1 != 0 { 16f32 } else { 0f32 };
+                    y[ys_index] = d1 * ((ql & 0xF) as f32 + to_add) - m1;
                     ys_index += 1;
                 }
                 for (ql, qh) in ql.iter().zip(qh) {
-                    let to_add = if qh & u2 != 0 { 16 } else { 1 };
-                    y[ys_index] = d2 * ((ql >> 4) + to_add) as f32 - m2;
+                    let to_add = if qh & u2 != 0 { 16f32 } else { 0f32 };
+                    y[ys_index] = d2 * ((ql >> 4) as f32 + to_add) - m2;
                     ys_index += 1;
                 }
                 is += 2;

diff --git a/candle-core/tests/quantized_tests.rs b/candle-core/tests/quantized_tests.rs
@@ -407,7 +407,7 @@ fn quantize_q5k() -> Result<()> {
     let dst = round_vector(&dst);
     assert_eq!(
         [dst[0], dst[128], dst[256], dst[512], dst[800], dst[1023]],
-        [-0.499, -0.372, -0.249, 0.001, 0.279, 0.499]
+        [-0.5, -0.373, -0.25, 0.0, 0.279, 0.499]
     );
 
     let (src_big, mut dst_big) = get_test_vector(128.0, 1024);