On Tue, Apr 14, 2020 at 9:05 AM Bernard Zhao <[email protected]> wrote:
>
> On some processors, the / operate will call the compiler`s div lib,
> which is low efficient, We can replace the / operation with shift,
> so that we can replace the call of the division library with one
> shift assembly instruction.
>
> Signed-off-by: Bernard Zhao <[email protected]>
Applied. thanks.
Alex
> ---
> drivers/gpu/drm/amd/amdgpu/gmc_v6_0.c | 4 ++--
> drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c | 4 ++--
> drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c | 4 ++--
> 3 files changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v6_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v6_0.c
> index b205039..66cd078 100644
> --- a/drivers/gpu/drm/amd/amdgpu/gmc_v6_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/gmc_v6_0.c
> @@ -175,10 +175,10 @@ static int gmc_v6_0_mc_load_microcode(struct amdgpu_device *adev)
> amdgpu_ucode_print_mc_hdr(&hdr->header);
>
> adev->gmc.fw_version = le32_to_cpu(hdr->header.ucode_version);
> - regs_size = le32_to_cpu(hdr->io_debug_size_bytes) / (4 * 2);
> + regs_size = le32_to_cpu(hdr->io_debug_size_bytes) >> 3;
> new_io_mc_regs = (const __le32 *)
> (adev->gmc.fw->data + le32_to_cpu(hdr->io_debug_array_offset_bytes));
> - ucode_size = le32_to_cpu(hdr->header.ucode_size_bytes) / 4;
> + ucode_size = le32_to_cpu(hdr->header.ucode_size_bytes) >> 2;
> new_fw_data = (const __le32 *)
> (adev->gmc.fw->data + le32_to_cpu(hdr->header.ucode_array_offset_bytes));
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c
> index 9da9596..ca26d63 100644
> --- a/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c
> @@ -193,10 +193,10 @@ static int gmc_v7_0_mc_load_microcode(struct amdgpu_device *adev)
> amdgpu_ucode_print_mc_hdr(&hdr->header);
>
> adev->gmc.fw_version = le32_to_cpu(hdr->header.ucode_version);
> - regs_size = le32_to_cpu(hdr->io_debug_size_bytes) / (4 * 2);
> + regs_size = le32_to_cpu(hdr->io_debug_size_bytes) >> 3;
> io_mc_regs = (const __le32 *)
> (adev->gmc.fw->data + le32_to_cpu(hdr->io_debug_array_offset_bytes));
> - ucode_size = le32_to_cpu(hdr->header.ucode_size_bytes) / 4;
> + ucode_size = le32_to_cpu(hdr->header.ucode_size_bytes) >> 2;
> fw_data = (const __le32 *)
> (adev->gmc.fw->data + le32_to_cpu(hdr->header.ucode_array_offset_bytes));
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c
> index 27d83204..295039c 100644
> --- a/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c
> @@ -318,10 +318,10 @@ static int gmc_v8_0_tonga_mc_load_microcode(struct amdgpu_device *adev)
> amdgpu_ucode_print_mc_hdr(&hdr->header);
>
> adev->gmc.fw_version = le32_to_cpu(hdr->header.ucode_version);
> - regs_size = le32_to_cpu(hdr->io_debug_size_bytes) / (4 * 2);
> + regs_size = le32_to_cpu(hdr->io_debug_size_bytes) >> 3;
> io_mc_regs = (const __le32 *)
> (adev->gmc.fw->data + le32_to_cpu(hdr->io_debug_array_offset_bytes));
> - ucode_size = le32_to_cpu(hdr->header.ucode_size_bytes) / 4;
> + ucode_size = le32_to_cpu(hdr->header.ucode_size_bytes) >> 2;
> fw_data = (const __le32 *)
> (adev->gmc.fw->data + le32_to_cpu(hdr->header.ucode_array_offset_bytes));
>
> --
> 2.7.4
>
> _______________________________________________
> amd-gfx mailing list
> [email protected]
> https://lists.freedesktop.org/mailman/listinfo/amd-gfx
On Tue, 14 Apr 2020, Alex Deucher <[email protected]> wrote:
> On Tue, Apr 14, 2020 at 9:05 AM Bernard Zhao <[email protected]> wrote:
>>
>> On some processors, the / operate will call the compiler`s div lib,
>> which is low efficient, We can replace the / operation with shift,
>> so that we can replace the call of the division library with one
>> shift assembly instruction.
This was applied already, and it's not in a driver I look after... but
to me this feels like something that really should be
justified. Using >> instead of / for multiples of 2 division mattered 20
years ago, I'd be surprised if it still did on modern compilers.
BR,
Jani.
>>
>> Signed-off-by: Bernard Zhao <[email protected]>
>
> Applied. thanks.
>
> Alex
>
>> ---
>> drivers/gpu/drm/amd/amdgpu/gmc_v6_0.c | 4 ++--
>> drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c | 4 ++--
>> drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c | 4 ++--
>> 3 files changed, 6 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v6_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v6_0.c
>> index b205039..66cd078 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/gmc_v6_0.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/gmc_v6_0.c
>> @@ -175,10 +175,10 @@ static int gmc_v6_0_mc_load_microcode(struct amdgpu_device *adev)
>> amdgpu_ucode_print_mc_hdr(&hdr->header);
>>
>> adev->gmc.fw_version = le32_to_cpu(hdr->header.ucode_version);
>> - regs_size = le32_to_cpu(hdr->io_debug_size_bytes) / (4 * 2);
>> + regs_size = le32_to_cpu(hdr->io_debug_size_bytes) >> 3;
>> new_io_mc_regs = (const __le32 *)
>> (adev->gmc.fw->data + le32_to_cpu(hdr->io_debug_array_offset_bytes));
>> - ucode_size = le32_to_cpu(hdr->header.ucode_size_bytes) / 4;
>> + ucode_size = le32_to_cpu(hdr->header.ucode_size_bytes) >> 2;
>> new_fw_data = (const __le32 *)
>> (adev->gmc.fw->data + le32_to_cpu(hdr->header.ucode_array_offset_bytes));
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c
>> index 9da9596..ca26d63 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c
>> @@ -193,10 +193,10 @@ static int gmc_v7_0_mc_load_microcode(struct amdgpu_device *adev)
>> amdgpu_ucode_print_mc_hdr(&hdr->header);
>>
>> adev->gmc.fw_version = le32_to_cpu(hdr->header.ucode_version);
>> - regs_size = le32_to_cpu(hdr->io_debug_size_bytes) / (4 * 2);
>> + regs_size = le32_to_cpu(hdr->io_debug_size_bytes) >> 3;
>> io_mc_regs = (const __le32 *)
>> (adev->gmc.fw->data + le32_to_cpu(hdr->io_debug_array_offset_bytes));
>> - ucode_size = le32_to_cpu(hdr->header.ucode_size_bytes) / 4;
>> + ucode_size = le32_to_cpu(hdr->header.ucode_size_bytes) >> 2;
>> fw_data = (const __le32 *)
>> (adev->gmc.fw->data + le32_to_cpu(hdr->header.ucode_array_offset_bytes));
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c
>> index 27d83204..295039c 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c
>> @@ -318,10 +318,10 @@ static int gmc_v8_0_tonga_mc_load_microcode(struct amdgpu_device *adev)
>> amdgpu_ucode_print_mc_hdr(&hdr->header);
>>
>> adev->gmc.fw_version = le32_to_cpu(hdr->header.ucode_version);
>> - regs_size = le32_to_cpu(hdr->io_debug_size_bytes) / (4 * 2);
>> + regs_size = le32_to_cpu(hdr->io_debug_size_bytes) >> 3;
>> io_mc_regs = (const __le32 *)
>> (adev->gmc.fw->data + le32_to_cpu(hdr->io_debug_array_offset_bytes));
>> - ucode_size = le32_to_cpu(hdr->header.ucode_size_bytes) / 4;
>> + ucode_size = le32_to_cpu(hdr->header.ucode_size_bytes) >> 2;
>> fw_data = (const __le32 *)
>> (adev->gmc.fw->data + le32_to_cpu(hdr->header.ucode_array_offset_bytes));
>>
>> --
>> 2.7.4
>>
>> _______________________________________________
>> amd-gfx mailing list
>> [email protected]
>> https://lists.freedesktop.org/mailman/listinfo/amd-gfx
> _______________________________________________
> dri-devel mailing list
> [email protected]
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
--
Jani Nikula, Intel Open Source Graphics Center