diff options
Diffstat (limited to 'main/pango/fix-x86.patch')
| -rw-r--r-- | main/pango/fix-x86.patch | 107 |
1 files changed, 0 insertions, 107 deletions
diff --git a/main/pango/fix-x86.patch b/main/pango/fix-x86.patch deleted file mode 100644 index 05c6bc5cea7..00000000000 --- a/main/pango/fix-x86.patch +++ /dev/null @@ -1,107 +0,0 @@ -From d439eea5909b13a138930a668b3114a1dc4904b4 Mon Sep 17 00:00:00 2001 -From: =?UTF-8?q?Marco=20Trevisan=20=28Trevi=C3=B1o=29?= <mail@3v1n0.net> -Date: Tue, 13 Jul 2021 21:08:31 +0200 -Subject: [PATCH] font-desc: Use local volatile double values to store sizes - -Under i386 multiplying double and integer values and cast it to integer -may end up to compute the wrong value when only 387 FPU is used, because -the temporary value will be stored in a register whose precision isn't -good enough. -And so, some multiplications which are expected to produce an integer, -will actually return a truncated value, that will be eventually floored. - -An example is 1.2 * 12800 that is clearly 15360.0, but will produce -15359 when casted to int in the said i386 environment. - -So use a temporary double variable to ensure that we do this computation -in the double scope, before casting to int. - -And this will avoid using the said register, even when using more -aggressive optimizations (as per marking the local variable volatile). - -Fixes: https://gitlab.gnome.org/GNOME/pango/-/issues/580 ---- - pango/pango-attributes.c | 10 ++++++++-- - pango/pango-markup.c | 16 ++++++++++------ - pango/pangofc-fontmap.c | 8 +++++++- - 3 files changed, 25 insertions(+), 9 deletions(-) - -diff --git a/pango/pango-attributes.c b/pango/pango-attributes.c -index fd0df205..26d08404 100644 ---- a/pango/pango-attributes.c -+++ b/pango/pango-attributes.c -@@ -2382,10 +2382,16 @@ pango_attr_iterator_get_font (PangoAttrIterator *iterator, - - if (have_scale) - { -+ /* We need to use a local variable to ensure that the compiler won't -+ * implicitly cast it to integer while the result is kept in registers, -+ * leading to a wrong approximation in i386 (with 387 FPU) -+ */ -+ volatile double size = scale * pango_font_description_get_size (desc); -+ - if (pango_font_description_get_size_is_absolute (desc)) -- pango_font_description_set_absolute_size (desc, scale * pango_font_description_get_size (desc)); -+ pango_font_description_set_absolute_size (desc, size); - else -- pango_font_description_set_size (desc, scale * pango_font_description_get_size (desc)); -+ pango_font_description_set_size (desc, size); - } - } - -diff --git a/pango/pango-markup.c b/pango/pango-markup.c -index 38e908c5..2828eab3 100644 ---- a/pango/pango-markup.c -+++ b/pango/pango-markup.c -@@ -294,12 +294,16 @@ markup_data_close_tag (MarkupData *md) - - if (ot->has_base_font_size) - { -- /* Create a font using the absolute point size -- * as the base size to be scaled from -- */ -- a = pango_attr_size_new (scale_factor (ot->scale_level, -- 1.0) * -- ot->base_font_size); -+ /* Create a font using the absolute point size as the base size -+ * to be scaled from. -+ * We need to use a local variable to ensure that the compiler won't -+ * implicitly cast it to integer while the result is kept in registers, -+ * leading to a wrong approximation in i386 (with 387 FPU) -+ */ -+ volatile double size; -+ -+ size = scale_factor (ot->scale_level, 1.0) * ot->base_font_size; -+ a = pango_attr_size_new (size); - } - else - { -diff --git a/pango/pangofc-fontmap.c b/pango/pangofc-fontmap.c -index 62f2cd4b..9c008411 100644 ---- a/pango/pangofc-fontmap.c -+++ b/pango/pangofc-fontmap.c -@@ -2789,6 +2789,7 @@ pango_fc_font_description_from_pattern (FcPattern *pattern, gboolean include_siz - { - FcMatrix *fc_matrix; - double scale_factor = 1; -+ volatile double scaled_size; - - if (FcPatternGetMatrix (pattern, FC_MATRIX, 0, &fc_matrix) == FcResultMatch) - { -@@ -2802,7 +2803,12 @@ pango_fc_font_description_from_pattern (FcPattern *pattern, gboolean include_siz - scale_factor = pango_matrix_get_font_scale_factor (&mat); - } - -- pango_font_description_set_size (desc, scale_factor * size * PANGO_SCALE); -+ /* We need to use a local variable to ensure that the compiler won't -+ * implicitly cast it to integer while the result is kept in registers, -+ * leading to a wrong approximation in i386 (with 387 FPU) -+ */ -+ scaled_size = scale_factor * size * PANGO_SCALE; -+ pango_font_description_set_size (desc, scaled_size); - } - - /* gravity is a bit different. we don't want to set it if it was not set on --- -GitLab - |