From 2b565bb6f3112644b4b53278513f4fe7f501d536 Mon Sep 17 00:00:00 2001 From: Victor Stinner Date: Fri, 12 Dec 2014 13:19:00 +0100 Subject: [PATCH] Issue #18028: Fix aliasing issue in READ_TIMESTAMP() of ceval.c on x86_64, when Python is configure with --with-tsc. Patch written by Christian Heimes. --- Python/ceval.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/Python/ceval.c b/Python/ceval.c index 682a1e7e48..fa6bb60517 100644 --- a/Python/ceval.c +++ b/Python/ceval.c @@ -66,9 +66,11 @@ ppc_getcounter(uint64 *v) even in 64-bit mode, we need to use "a" and "d" for the lower and upper 32-bit pieces of the result. */ -#define READ_TIMESTAMP(val) \ - __asm__ __volatile__("rdtsc" : \ - "=a" (((int*)&(val))[0]), "=d" (((int*)&(val))[1])); +#define READ_TIMESTAMP(val) do { \ + unsigned int h, l; \ + __asm__ __volatile__("rdtsc" : "=a" (l), "=d" (h)); \ + (val) = ((uint64)l) | (((uint64)h) << 32); \ + } while(0) #else -- 2.50.1