package/boost/0004-Corrected-register-usage-in-x86-DCAS-asm-blocks.patch

   1 From a67cc1b055cf09f371e2eca544884634a1ccc886 Mon Sep 17 00:00:00 2001
   2 From: Andrey Semashev <andrey.semashev@gmail.com>
   3 Date: Sun, 8 Jan 2017 18:09:12 +0300
   4 Subject: [PATCH] Corrected register usage in x86 DCAS asm blocks.
   5
   6 In some of the asm blocks eax was modified as a result of cmpxchg8b but that
   7 was not reflected in the register constraints. This could cause incorrect code
   8 being generated.
   9
  10 Fetch from:
  11 https://github.com/boostorg/atomic/commit/a67cc1b055cf09f371e2eca544884634a1ccc886
  12
  13 [Adjust github patch to tarball release]
  14 Signed-off-by: Jörg Krause <joerg.krause@embedded.rocks>
  15 ---
  16  boost/atomic/detail/ops_gcc_x86_dcas.hpp | 14 ++++++++------
  17  1 file changed, 8 insertions(+), 6 deletions(-)
  18
  19 diff --git a/boost/atomic/detail/ops_gcc_x86_dcas.hpp b/boost/atomic/detail/ops_gcc_x86_dcas.hpp
  20 index 2f51182..e356e8c 100644
  21 --- a/boost/atomic/detail/ops_gcc_x86_dcas.hpp
  22 +++ b/boost/atomic/detail/ops_gcc_x86_dcas.hpp
  23 @@ -73,6 +73,7 @@ struct gcc_dcas_x86
  24          {
  25  #if !defined(BOOST_ATOMIC_DETAIL_NO_ASM_IMPLIED_ZERO_DISPLACEMENTS)
  26  #if defined(__PIC__)
  27 +            uint32_t v_lo = (uint32_t)v;
  28              uint32_t scratch;
  29              __asm__ __volatile__
  30              (
  31 @@ -84,8 +85,8 @@ struct gcc_dcas_x86
  32                  "1: lock; cmpxchg8b %[dest]\n\t"
  33                  "jne 1b\n\t"
  34                  "movl %[scratch], %%ebx\n\t"
  35 -                : [scratch] "=m" (scratch), [dest] "=o" (storage)
  36 -                : [value_lo] "a" ((uint32_t)v), "c" ((uint32_t)(v >> 32))
  37 +                : [scratch] "=m" (scratch), [dest] "=o" (storage), [value_lo] "+a" (v_lo)
  38 +                : "c" ((uint32_t)(v >> 32))
  39                  : BOOST_ATOMIC_DETAIL_ASM_CLOBBER_CC_COMMA "edx", "memory"
  40              );
  41  #else // defined(__PIC__)
  42 @@ -103,6 +104,7 @@ struct gcc_dcas_x86
  43  #endif // defined(__PIC__)
  44  #else // !defined(BOOST_ATOMIC_DETAIL_NO_ASM_IMPLIED_ZERO_DISPLACEMENTS)
  45  #if defined(__PIC__)
  46 +            uint32_t v_lo = (uint32_t)v;
  47              uint32_t scratch;
  48              __asm__ __volatile__
  49              (
  50 @@ -115,11 +117,11 @@ struct gcc_dcas_x86
  51                  "jne 1b\n\t"
  52                  "movl %[scratch], %%ebx\n\t"
  53  #if !defined(BOOST_ATOMIC_DETAIL_NO_ASM_CONSTRAINT_ALTERNATIVES)
  54 -                : [scratch] "=m,m" (scratch)
  55 -                : [value_lo] "a,a" ((uint32_t)v), "c,c" ((uint32_t)(v >> 32)), [dest] "D,S" (&storage)
  56 +                : [scratch] "=m,m" (scratch), [value_lo] "+a,a" (v_lo)
  57 +                : "c,c" ((uint32_t)(v >> 32)), [dest] "D,S" (&storage)
  58  #else
  59 -                : [scratch] "=m" (scratch)
  60 -                : [value_lo] "a" ((uint32_t)v), "c" ((uint32_t)(v >> 32)), [dest] "D" (&storage)
  61 +                : [scratch] "=m" (scratch), [value_lo] "+a" (v_lo)
  62 +                : "c" ((uint32_t)(v >> 32)), [dest] "D" (&storage)
  63  #endif
  64                  : BOOST_ATOMIC_DETAIL_ASM_CLOBBER_CC_COMMA "edx", "memory"
  65              );