On Tue, 14 Apr 2020, Alex Deucher <alexdeucher@xxxxxxxxx> wrote: > On Tue, Apr 14, 2020 at 9:05 AM Bernard Zhao <bernard@xxxxxxxx> 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 <bernard@xxxxxxxx> > > 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 >> amd-gfx@xxxxxxxxxxxxxxxxxxxxx >> https://lists.freedesktop.org/mailman/listinfo/amd-gfx > _______________________________________________ > dri-devel mailing list > dri-devel@xxxxxxxxxxxxxxxxxxxxx > https://lists.freedesktop.org/mailman/listinfo/dri-devel -- Jani Nikula, Intel Open Source Graphics Center _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
