diff options
Diffstat (limited to 'gnu/packages/patches/jamvm-2.0.0-opcode-guard.patch')
| -rw-r--r-- | gnu/packages/patches/jamvm-2.0.0-opcode-guard.patch | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/gnu/packages/patches/jamvm-2.0.0-opcode-guard.patch b/gnu/packages/patches/jamvm-2.0.0-opcode-guard.patch new file mode 100644 index 0000000000..5415c27a62 --- /dev/null +++ b/gnu/packages/patches/jamvm-2.0.0-opcode-guard.patch @@ -0,0 +1,35 @@ +From ca11b53896365c948426974cb90e8f71c70d123b Mon Sep 17 00:00:00 2001 +From: Simon South <simon@simonsouth.net> +Date: Sun, 31 May 2020 20:36:43 -0400 +Subject: [PATCH] Guard floating-point opcodes with explicit memory barrier + +--- + src/interp/engine/interp-inlining.h | 11 ++++++++++- + 1 file changed, 10 insertions(+), 1 deletion(-) + +diff --git a/src/interp/engine/interp-inlining.h b/src/interp/engine/interp-inlining.h +index 3339b0e..4ee5c5a 100644 +--- a/src/interp/engine/interp-inlining.h ++++ b/src/interp/engine/interp-inlining.h +@@ -78,8 +78,17 @@ + 4.3, we need to insert a label, and ensure its address + is taken (to stop it being optimised out). However, + this reduces performance on PowerPC by approx 1 - 2%. ++ ++ With gcc 5 and newer an asm statement with a "memory" ++ clobber argument explicitly sets a memory barrier for the ++ compiler, preventing it from reordering memory accesses ++ in a way that breaks decaching. + */ +-#if (__GNUC__ == 4) && (__GNUC_MINOR__ >= 3) ++#if (__GNUC__ > 4) ++#define DEF_GUARD_TABLE(level) /* none */ ++#define GUARD(opcode, level) __asm__("" ::: "memory"); ++#define GUARD_TBLS /* none */ ++#elif (__GNUC__ == 4) && (__GNUC_MINOR__ >= 3) + #define DEF_GUARD_TABLE(level) DEF_HANDLER_TABLE(level, GUARD) + #define GUARD(opcode, level) label(opcode, level, GUARD) + #define GUARD_TBLS , HNDLR_TBLS(GUARD) +-- +2.26.2 + |