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Date: Tue,  6 Mar 2018 17:55:02 +0100
From: Denys Vlasenko <vda.linux@...glemail.com>
To: Rich Felker <dalias@...c.org>
Cc: Denys Vlasenko <vda.linux@...glemail.com>,
	musl <musl@...ts.openwall.com>
Subject: [PATCH] reduce size of struct __libc by using narrower integers

can_do_threads, threaded and secure are boolean flags, can use bytes
instead of full word ints.

tls_align and page_size are surely smaller than 4GB, no need to use
potentially 64-bit size_t.

Signed-off-by: Denys Vlasenko <vda.linux@...glemail.com>
CC: musl <musl@...ts.openwall.com>
---
 ldso/dynlink.c      |  3 ++-
 src/internal/libc.h | 11 ++++++-----
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/ldso/dynlink.c b/ldso/dynlink.c
index 9bf6924b..67d36395 100644
--- a/ldso/dynlink.c
+++ b/ldso/dynlink.c
@@ -124,8 +124,9 @@ static jmp_buf *rtld_fail;
 static pthread_rwlock_t lock;
 static struct debug debug;
 static struct tls_module *tls_tail;
-static size_t tls_cnt, tls_offset, tls_align = MIN_TLS_ALIGN;
+static size_t tls_cnt, tls_offset;
 static size_t static_tls_cnt;
+static unsigned tls_align = MIN_TLS_ALIGN;
 static pthread_mutex_t init_fini_lock = { ._m_type = PTHREAD_MUTEX_RECURSIVE };
 static struct fdpic_loadmap *app_loadmap;
 static struct fdpic_dummy_loadmap app_dummy_loadmap;
diff --git a/src/internal/libc.h b/src/internal/libc.h
index 5e145183..3cd44e90 100644
--- a/src/internal/libc.h
+++ b/src/internal/libc.h
@@ -18,14 +18,15 @@ struct tls_module {
 };
 
 struct __libc {
-	int can_do_threads;
-	int threaded;
-	int secure;
+	char can_do_threads;
+	char threaded;
+	char secure;
 	volatile int threads_minus_1;
 	size_t *auxv;
 	struct tls_module *tls_head;
-	size_t tls_size, tls_align, tls_cnt;
-	size_t page_size;
+	size_t tls_size, tls_cnt;
+	unsigned tls_align;
+	unsigned page_size;
 	struct __locale_struct global_locale;
 };
 
-- 
2.16.2

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