[glibc/azanella/ubsan-undef] math: Fix UB on sinpif
Adhemerval Zanella
azanella@sourceware.org
Fri Apr 25 19:53:17 GMT 2025
https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=4cbda6298b19425fd326881b648ecdafcc26de16
commit 4cbda6298b19425fd326881b648ecdafcc26de16
Author: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Date: Mon Apr 21 17:27:07 2025 -0300
math: Fix UB on sinpif
The left shift overflows for 'int', use uint32_t instead. It syncs
with CORE-MATH commit bbfabd99.
Diff:
---
sysdeps/ieee754/flt-32/s_sinpif.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/sysdeps/ieee754/flt-32/s_sinpif.c b/sysdeps/ieee754/flt-32/s_sinpif.c
index 99a8bbbcf3..c0d15e777b 100644
--- a/sysdeps/ieee754/flt-32/s_sinpif.c
+++ b/sysdeps/ieee754/flt-32/s_sinpif.c
@@ -3,7 +3,7 @@
Copyright (c) 2022-2025 Alexei Sibidanov.
The original version of this file was copied from the CORE-MATH
-project (src/binary32/sinpi/sinpif.c, revision f786e13).
+project (src/binary32/sinpi/sinpif.c, revision bbfabd99.
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
@@ -51,7 +51,7 @@ __sinpif (float x)
{
if (__glibc_unlikely (s < -6))
return copysignf (0.0f, x);
- int32_t iq = m << (-s - 1);
+ int32_t iq = (uint32_t)m << (-s - 1);
iq &= 127;
if (iq == 0 || iq == 64)
return copysignf (0.0f, x);
@@ -63,10 +63,10 @@ __sinpif (float x)
return z * (0x1.921fb54442d18p+1 + z2 * (-0x1.4abbce625be53p+2));
}
int32_t si = 25 - s;
- if (__glibc_unlikely (si >= 0 && (m << si) == 0))
+ if (__glibc_unlikely (si >= 0 && ((uint32_t)m << si) == 0))
return copysignf (0.0f, x);
- int32_t k = m << (31 - s);
+ int32_t k = (uint32_t)m << (31 - s);
double z = k, z2 = z * z;
double fs = SN[0] + z2 * (SN[1] + z2 * SN[2]);
double fc = CN[0] + z2 * (CN[1] + z2 * CN[2]);
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