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| author | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2024-03-05 14:02:57 -0300 |
|---|---|---|
| committer | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2024-03-12 14:38:08 -0300 |
| commit | 2149da36836bc32cd66359ca37bab5884af7e81f (patch) | |
| tree | a238d5f1dfcacdd229f9c4c3d479e8d304195116 /sysdeps/unix/sysv/linux/riscv/Makefile | |
| parent | 2173173d57971d042c0ad4b281431ae127e9b5b8 (diff) | |
| download | glibc-2149da36836bc32cd66359ca37bab5884af7e81f.zip glibc-2149da36836bc32cd66359ca37bab5884af7e81f.tar.gz glibc-2149da36836bc32cd66359ca37bab5884af7e81f.tar.bz2 | |
riscv: Fix alignment-ignorant memcpy implementation
The memcpy optimization (commit 587a1290a1af7bee6db) has a series
of mistakes:
- The implementation is wrong: the chunk size calculation is wrong
leading to invalid memory access.
- It adds ifunc supports as default, so --disable-multi-arch does
not work as expected for riscv.
- It mixes Linux files (memcpy ifunc selection which requires the
vDSO/syscall mechanism) with generic support (the memcpy
optimization itself).
- There is no __libc_ifunc_impl_list, which makes testing only
check the selected implementation instead of all supported
by the system.
This patch also simplifies the required bits to enable ifunc: there
is no need to memcopy.h; nor to add Linux-specific files.
The __memcpy_noalignment tail handling now uses a branchless strategy
similar to aarch64 (overlap 32-bits copies for sizes 4..7 and byte
copies for size 1..3).
Checked on riscv64 and riscv32 by explicitly enabling the function
on __libc_ifunc_impl_list on qemu-system.
Changes from v1:
* Implement the memcpy in assembly to correctly handle RISCV
strict-alignment.
Reviewed-by: Evan Green <evan@rivosinc.com>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Diffstat (limited to 'sysdeps/unix/sysv/linux/riscv/Makefile')
| -rw-r--r-- | sysdeps/unix/sysv/linux/riscv/Makefile | 9 |
1 files changed, 0 insertions, 9 deletions
diff --git a/sysdeps/unix/sysv/linux/riscv/Makefile b/sysdeps/unix/sysv/linux/riscv/Makefile index 398ff74..04abf22 100644 --- a/sysdeps/unix/sysv/linux/riscv/Makefile +++ b/sysdeps/unix/sysv/linux/riscv/Makefile @@ -15,15 +15,6 @@ ifeq ($(subdir),stdlib) gen-as-const-headers += ucontext_i.sym endif -ifeq ($(subdir),string) -sysdep_routines += \ - memcpy \ - memcpy-generic \ - memcpy_noalignment \ - # sysdep_routines - -endif - abi-variants := ilp32 ilp32d lp64 lp64d ifeq (,$(filter $(default-abi),$(abi-variants))) |