From: Szabolcs Nagy <nsz@port70.net>
Date: Sun, 13 Oct 2019 14:54:31 +0000 (+0000)
Subject: math: fix signed int left shift ub in sqrt
X-Git-Tag: v1.1.24~1
X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=e858063070eedb7fe78c37eba5177d8c5cfccfa6;p=oweals%2Fmusl.git

math: fix signed int left shift ub in sqrt

Both sqrt and sqrtf shifted the signed exponent as signed int to adjust
the bit representation of the result. There are signed right shifts too
in the code but those are implementation defined and are expected to
compile to arithmetic shift on supported compilers and targets.
---

diff --git a/src/math/sqrt.c b/src/math/sqrt.c
index b2775673..f1f6d76c 100644
--- a/src/math/sqrt.c
+++ b/src/math/sqrt.c
@@ -179,7 +179,6 @@ double sqrt(double x)
 	ix1 = q1>>1;
 	if (q&1)
 		ix1 |= sign;
-	ix0 += m << 20;
-	INSERT_WORDS(z, ix0, ix1);
+	INSERT_WORDS(z, ix0 + ((uint32_t)m << 20), ix1);
 	return z;
 }
diff --git a/src/math/sqrtf.c b/src/math/sqrtf.c
index 28cb4ad3..d6ace38a 100644
--- a/src/math/sqrtf.c
+++ b/src/math/sqrtf.c
@@ -78,7 +78,6 @@ float sqrtf(float x)
 		}
 	}
 	ix = (q>>1) + 0x3f000000;
-	ix += m << 23;
-	SET_FLOAT_WORD(z, ix);
+	SET_FLOAT_WORD(z, ix + ((uint32_t)m << 23));
 	return z;
 }