diff options
Diffstat (limited to 'meta-xilinx-bsp/recipes-microblaze/gcc/gcc-7/0003-microblaze-sync.md-Correct-behaviour-and-define-side.patch')
| -rw-r--r-- | meta-xilinx-bsp/recipes-microblaze/gcc/gcc-7/0003-microblaze-sync.md-Correct-behaviour-and-define-side.patch | 76 |
1 files changed, 0 insertions, 76 deletions
diff --git a/meta-xilinx-bsp/recipes-microblaze/gcc/gcc-7/0003-microblaze-sync.md-Correct-behaviour-and-define-side.patch b/meta-xilinx-bsp/recipes-microblaze/gcc/gcc-7/0003-microblaze-sync.md-Correct-behaviour-and-define-side.patch deleted file mode 100644 index 9336291b..00000000 --- a/meta-xilinx-bsp/recipes-microblaze/gcc/gcc-7/0003-microblaze-sync.md-Correct-behaviour-and-define-side.patch +++ /dev/null @@ -1,76 +0,0 @@ -From 6c7a10a9e077d0221cc9a6c5f5a6365815c1dca4 Mon Sep 17 00:00:00 2001 -From: Nathan Rossi <nathan@nathanrossi.com> -Date: Mon, 12 Jun 2017 00:28:42 +1000 -Subject: [PATCH 3/4] microblaze/sync.md: Correct behaviour and define - side-effects - -This change corrects the behaviour with regards to the bool output. -Previously the definition would set the bool operand to true (non-zero) -on failure, specifically at the 'cmp' against the expected operand which -would be set non-zero when the memory != expected value. Instead of -using the bool operand as the compare result use the clobbered %8 -operand for temporary comparison result and set the bool operand at the -end of the definition to true (in this case the immediate value of 1). -Also to ensure that the bool operand is 0 in all other cases the first -instruction which is intended as a clear of the carry bit is reused to -set the bool operand to 0 at the same time as clearing the carry bit. -And finally the jump offsets were updated - -Additional to the behaviour change this change defines the side-effects -of the atomic_compare_and_swap. Specifically the side effects where the -bool and val operands are modified/set based on the value of the memory -content. This prevents certain optimization behaviour from incorrectly -optimizing away code. An example of this is the snippet below, where in -certain cases the comparison is optimized away entirely. - - mem = 2; - if (atomic_compare_and_swap(&mem, ...) == 2) - ... - -Signed-off-by: Nathan Rossi <nathan@nathanrossi.com> -Upstream-Status: Unsubmitted ---- - gcc/config/microblaze/sync.md | 14 ++++++++------ - 1 file changed, 8 insertions(+), 6 deletions(-) - -diff --git a/gcc/config/microblaze/sync.md b/gcc/config/microblaze/sync.md -index 8125bd8d63..605a9a969e 100644 ---- a/gcc/config/microblaze/sync.md -+++ b/gcc/config/microblaze/sync.md -@@ -18,9 +18,10 @@ - ;; <http://www.gnu.org/licenses/>. - - (define_insn "atomic_compare_and_swapsi" -- [(match_operand:SI 0 "register_operand" "=&d") ;; bool output -- (match_operand:SI 1 "register_operand" "=&d") ;; val output -- (match_operand:SI 2 "nonimmediate_operand" "+Q") ;; memory -+ [(set (match_operand:SI 0 "register_operand" "=&d") ;; bool output -+ (match_operand:SI 2 "nonimmediate_operand" "+Q")) ;; memory -+ (set (match_operand:SI 1 "register_operand" "=&d") ;; val output -+ (match_dup 2)) - (match_operand:SI 3 "register_operand" "d") ;; expected value - (match_operand:SI 4 "register_operand" "d") ;; desired value - (match_operand:SI 5 "const_int_operand" "") ;; is_weak -@@ -29,15 +30,16 @@ - (clobber (match_scratch:SI 8 "=&d"))] - "" - { -- output_asm_insn ("addc \tr0,r0,r0", operands); -+ output_asm_insn ("add \t%0,r0,r0", operands); - output_asm_insn ("lwx \t%1,%y2,r0", operands); - output_asm_insn ("addic\t%8,r0,0", operands); - output_asm_insn ("bnei \t%8,.-8", operands); -- output_asm_insn ("cmp \t%0,%1,%3", operands); -- output_asm_insn ("bnei \t%0,.+16", operands); -+ output_asm_insn ("cmp \t%8,%1,%3", operands); -+ output_asm_insn ("bnei \t%8,.+20", operands); - output_asm_insn ("swx \t%4,%y2,r0", operands); - output_asm_insn ("addic\t%8,r0,0", operands); - output_asm_insn ("bnei \t%8,.-28", operands); -+ output_asm_insn ("addi \t%0,r0,1", operands); - return ""; - } - ) --- -2.11.0 - |