From 5fa6c88b179d2167c0c4b99b75a9d503990ef181 Mon Sep 17 00:00:00 2001
From: biondizzle <biondizzle@gmail.com>
Date: Sat, 30 May 2026 22:51:10 +0000
Subject: [PATCH] Fix: replace FP4 Inf with 24 (avoid NaN in dequant)

---
 single_shot_inference.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/single_shot_inference.py b/single_shot_inference.py
index 601d8a4e..1ed2d3b7 100644
--- a/single_shot_inference.py
+++ b/single_shot_inference.py
@@ -28,7 +28,7 @@ PROMPT = "The capital of France is"
 # FP4 E2M1 lookup table: index → float value (unsigned)
 # E2M1: 1-bit sign, 2-bit exp (bias=1), 1-bit mantissa
 # Values: 0, 2, 3, 4, 6, 8, 12, Inf  (for exp 00,01,10,11 × mantissa 0,1)
-FP4_LUT = torch.tensor([0., 2., 3., 4., 6., 8., 12., float('inf')])
+FP4_LUT = torch.tensor([0., 2., 3., 4., 6., 8., 12., 24.])  # E2M1: last value (0b111) is nominally Inf, use 24 (2^(2+1) * 1.5)
 
 def dequant_nvfp4_weight(
     weight: torch.Tensor,           # (out, in/2) uint8