From 6559eae72cd55939f477f6d9ba45c228823c5b06 Mon Sep 17 00:00:00 2001
From: Laurent Mazare <laurent.mazare@gmail.com>
Date: Fri, 25 Aug 2023 18:21:37 +0100
Subject: [PATCH] Avoid some transmutes. (#607)

---
 candle-core/src/quantized/k_quants.rs | 15 +++++----------
 1 file changed, 5 insertions(+), 10 deletions(-)

diff --git a/candle-core/src/quantized/k_quants.rs b/candle-core/src/quantized/k_quants.rs
index 3aefa5df..cdea2434 100644
--- a/candle-core/src/quantized/k_quants.rs
+++ b/candle-core/src/quantized/k_quants.rs
@@ -4,6 +4,7 @@ use super::utils::{
 };
 use super::GgmlDType;
 use crate::Result;
+use byteorder::{ByteOrder, LittleEndian};
 use half::f16;
 use rayon::prelude::*;
 
@@ -308,7 +309,7 @@ impl GgmlType for BlockQ5_0 {
         let nb = k / QK5_0;
         for i in 0..nb {
             let d = xs[i].d.to_f32();
-            let qh: u32 = unsafe { std::mem::transmute_copy(&xs[i].qh) };
+            let qh: u32 = LittleEndian::read_u32(&xs[i].qh);
 
             for j in 0..(QK5_0 / 2) {
                 let xh_0 = (((qh >> j) << 4) & 0x10) as u8;
@@ -349,7 +350,7 @@ impl GgmlType for BlockQ5_1 {
         for i in 0..nb {
             let d = xs[i].d.to_f32();
             let m = xs[i].m.to_f32();
-            let qh: u32 = unsafe { std::mem::transmute_copy(&xs[i].qh) };
+            let qh: u32 = LittleEndian::read_u32(&xs[i].qh);
 
             for j in 0..(QK5_1 / 2) {
                 let xh_0 = (((qh >> j) << 4) & 0x10) as u8;
@@ -719,10 +720,7 @@ impl GgmlType for BlockQ3K {
 
             a = &mut aux8[..];
 
-            let aux_raw = unsafe {
-                std::mem::transmute::<&mut [u8; 12], &mut [u32; 3]>(&mut x.scales.clone())
-            };
-            auxs[0..3].copy_from_slice(aux_raw);
+            LittleEndian::read_u32_into(&x.scales, &mut auxs[0..3]);
 
             let tmp = auxs[2];
             auxs[2] = ((auxs[0] >> 4) & KMASK2) | (((tmp >> 4) & KMASK1) << 4);
@@ -852,10 +850,7 @@ impl GgmlType for BlockQ3K {
         for (block, y) in group_for_dequantization(xs, ys)? {
             //Reconstruct the scales
             let mut aux = [0; 4];
-            let aux_raw = unsafe {
-                std::mem::transmute::<&mut [u8; 12], &mut [u32; 3]>(&mut block.scales.clone())
-            };
-            aux[0..3].copy_from_slice(aux_raw);
+            LittleEndian::read_u32_into(&block.scales, &mut aux[0..3]);
 
             let tmp = aux[2];
             aux[2] = ((aux[0] >> 4) & KMASK2) | (((tmp >> 4) & KMASK1) << 4);