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[7/8] math: Fix UB on erfcf

Message ID 20250425205618.360232-8-adhemerval.zanella@linaro.org
State New
Headers show
Series Fix UB in math implementations | expand

Commit Message

Adhemerval Zanella April 25, 2025, 8:54 p.m. UTC 
The left shift overflows for 'int', use uint64_t instead.  It syncs
with CORE-MATH commit d0a2be200cbc1344d800d9ef0ebee9ad67dd3ad8.

Checked on aarch64-linux-gnu, x86_64-linux-gnu, and i686-linux-gnu.
---
 sysdeps/ieee754/flt-32/s_erfcf.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/sysdeps/ieee754/flt-32/s_erfcf.c b/sysdeps/ieee754/flt-32/s_erfcf.c
index 3dae2a0b0e..955f129148 100644
--- a/sysdeps/ieee754/flt-32/s_erfcf.c
+++ b/sysdeps/ieee754/flt-32/s_erfcf.c
@@ -3,7 +3,7 @@ 
 Copyright (c) 2023, 2024 Alexei Sibidanov.
 
 This file is part of the CORE-MATH project
-project (file src/binary32/erfc/erfcf.c revision bc385c2).
+project (file src/binary32/erfc/erfcf.c revision d0a2be20).
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
@@ -142,7 +142,7 @@  __erfcf (float xf)
   const double ln2l = 0x1.cf79abd6f5dc8p-47;
   uint64_t jt = asuint64 (fma (x2, iln2, -(1024 + 0x1p-8)));
   int64_t j = (int64_t) (jt << 12) >> 48;
-  double S = asdouble (((j >> 7) + (0x3ff | sgn << 11)) << 52);
+  double S = asdouble ((uint64_t)((j >> 7) + (0x3ff | sgn << 11)) << 52);
   static const double ch[] =
     {
       -0x1.ffffffffff333p-2, 0x1.5555555556a14p-3, -0x1.55556666659b4p-5,