diff options
Diffstat (limited to '0001-lib-prepare-zstd-for-preboot-environment.patch')
| -rw-r--r-- | 0001-lib-prepare-zstd-for-preboot-environment.patch | 94 |
1 files changed, 0 insertions, 94 deletions
diff --git a/0001-lib-prepare-zstd-for-preboot-environment.patch b/0001-lib-prepare-zstd-for-preboot-environment.patch deleted file mode 100644 index c40eada5066c..000000000000 --- a/0001-lib-prepare-zstd-for-preboot-environment.patch +++ /dev/null @@ -1,94 +0,0 @@ -From fd7d683915a466f631fbef2c89fb8b8c8655dbde Mon Sep 17 00:00:00 2001 -From: Nick Terrell <terrelln@fb.com> -Date: Thu, 20 Jun 2019 15:03:27 -0700 -Subject: [PATCH 1/7] lib: prepare zstd for preboot environment - -* Remove a double definition of the CHECK_F macro when the zstd - library is amalgamated. -* Switch ZSTD_copy8() to __builtin_memcpy(), because in the preboot - environment on x86 gcc can't inline `memcpy()` otherwise. -* Limit the gcc hack in ZSTD_wildcopy() to the broken gcc version. See - https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81388. - -These changes are necessary to get the build to work in the preboot -environment, and to get reasonable performance. ZSTD_copy8() and -ZSTD_wildcopy() are in the core of the zstd hot loop. So outlining -these calls to memcpy(), and having an extra branch are very -detrimental to performance. - -Reviewed-by: Kees Cook <keescook@chromium.org> -Tested-by: Sedat Dilek <sedat.dilek@gmail.com> -Signed-off-by: Nick Terrell <terrelln@fb.com> ---- - lib/zstd/fse_decompress.c | 9 +-------- - lib/zstd/zstd_internal.h | 14 ++++++++++++-- - 2 files changed, 13 insertions(+), 10 deletions(-) - -diff --git a/lib/zstd/fse_decompress.c b/lib/zstd/fse_decompress.c -index a84300e5a013..0b353530fb3f 100644 ---- a/lib/zstd/fse_decompress.c -+++ b/lib/zstd/fse_decompress.c -@@ -47,6 +47,7 @@ - ****************************************************************/ - #include "bitstream.h" - #include "fse.h" -+#include "zstd_internal.h" - #include <linux/compiler.h> - #include <linux/kernel.h> - #include <linux/string.h> /* memcpy, memset */ -@@ -60,14 +61,6 @@ - enum { FSE_static_assert = 1 / (int)(!!(c)) }; \ - } /* use only *after* variable declarations */ - --/* check and forward error code */ --#define CHECK_F(f) \ -- { \ -- size_t const e = f; \ -- if (FSE_isError(e)) \ -- return e; \ -- } -- - /* ************************************************************** - * Templates - ****************************************************************/ -diff --git a/lib/zstd/zstd_internal.h b/lib/zstd/zstd_internal.h -index 1a79fab9e13a..dac753397f86 100644 ---- a/lib/zstd/zstd_internal.h -+++ b/lib/zstd/zstd_internal.h -@@ -127,7 +127,14 @@ static const U32 OF_defaultNormLog = OF_DEFAULTNORMLOG; - * Shared functions to include for inlining - *********************************************/ - ZSTD_STATIC void ZSTD_copy8(void *dst, const void *src) { -- memcpy(dst, src, 8); -+ /* -+ * zstd relies heavily on gcc being able to analyze and inline this -+ * memcpy() call, since it is called in a tight loop. Preboot mode -+ * is compiled in freestanding mode, which stops gcc from analyzing -+ * memcpy(). Use __builtin_memcpy() to tell gcc to analyze this as a -+ * regular memcpy(). -+ */ -+ __builtin_memcpy(dst, src, 8); - } - /*! ZSTD_wildcopy() : - * custom version of memcpy(), can copy up to 7 bytes too many (8 bytes if length==0) */ -@@ -137,13 +144,16 @@ ZSTD_STATIC void ZSTD_wildcopy(void *dst, const void *src, ptrdiff_t length) - const BYTE* ip = (const BYTE*)src; - BYTE* op = (BYTE*)dst; - BYTE* const oend = op + length; -- /* Work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81388. -+#if defined(GCC_VERSION) && GCC_VERSION >= 70000 && GCC_VERSION < 70200 -+ /* -+ * Work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81388. - * Avoid the bad case where the loop only runs once by handling the - * special case separately. This doesn't trigger the bug because it - * doesn't involve pointer/integer overflow. - */ - if (length <= 8) - return ZSTD_copy8(dst, src); -+#endif - do { - ZSTD_copy8(op, ip); - op += 8; --- -2.28.0 - |