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39 lines
1.1 KiB
Diff
39 lines
1.1 KiB
Diff
From 688d3da0f1730daddbc954bbc2d27cc96ceee04c Mon Sep 17 00:00:00 2001
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From: Szabolcs Nagy <nsz@port70.net>
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Date: Tue, 4 Oct 2016 03:58:56 +0200
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Subject: math: fix pow signed shift ub
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j is int32_t and thus j<<31 is undefined if j==1, so j is changed to
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uint32_t locally as a quick fix, the generated code is not affected.
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(this is a strict conformance fix, future c standard may allow 1<<31,
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see DR 463. the bug was inherited from freebsd fdlibm, the proper fix
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is to use uint32_t for all bit hacks, but that requires more intrusive
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changes.)
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reported by Daniel Sabogal
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---
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src/math/pow.c | 4 ++--
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1 file changed, 2 insertions(+), 2 deletions(-)
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diff --git a/src/math/pow.c b/src/math/pow.c
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index b66f632..3ddc1b6 100644
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--- a/src/math/pow.c
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+++ b/src/math/pow.c
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@@ -125,11 +125,11 @@ double pow(double x, double y)
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else if (iy >= 0x3ff00000) {
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k = (iy>>20) - 0x3ff; /* exponent */
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if (k > 20) {
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- j = ly>>(52-k);
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+ uint32_t j = ly>>(52-k);
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if ((j<<(52-k)) == ly)
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yisint = 2 - (j&1);
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} else if (ly == 0) {
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- j = iy>>(20-k);
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+ uint32_t j = iy>>(20-k);
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if ((j<<(20-k)) == iy)
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yisint = 2 - (j&1);
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}
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--
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cgit v0.11.2
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