From: Nick Desaulniers ndesaulniers@google.com
commit 0f0727d971f6fdf8f1077180d495ddb9928f0c8b upstream.
arch/x86/Makefile disables SSE and SSE2 for the whole kernel. The AMDGPU drivers modified in this patch re-enable SSE but not SSE2. Turn on SSE2 to support emitting double precision floating point instructions rather than calls to non-existent (usually available from gcc_s or compiler_rt) floating point helper routines for Clang.
This was originally landed in: commit 10117450735c ("drm/amd/display: add -msse2 to prevent Clang from emitting libcalls to undefined SW FP routines") but reverted in: commit 193392ed9f69 ("Revert "drm/amd/display: add -msse2 to prevent Clang from emitting libcalls to undefined SW FP routines"") due to bugreports from GCC builds. Add guards to only do so for Clang.
Link: https://bugs.freedesktop.org/show_bug.cgi?id=109487 Link: https://github.com/ClangBuiltLinux/linux/issues/327
Suggested-by: Sedat Dilek sedat.dilek@gmail.com Suggested-by: Sami Tolvanen samitolvanen@google.com Signed-off-by: Nick Desaulniers ndesaulniers@google.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/gpu/drm/amd/display/dc/calcs/Makefile | 4 ++++ drivers/gpu/drm/amd/display/dc/dcn20/Makefile | 4 ++++ drivers/gpu/drm/amd/display/dc/dml/Makefile | 4 ++++ drivers/gpu/drm/amd/display/dc/dsc/Makefile | 4 ++++ 4 files changed, 16 insertions(+)
--- a/drivers/gpu/drm/amd/display/dc/calcs/Makefile +++ b/drivers/gpu/drm/amd/display/dc/calcs/Makefile @@ -32,6 +32,10 @@ endif
calcs_ccflags := -mhard-float -msse $(cc_stack_align)
+ifdef CONFIG_CC_IS_CLANG +calcs_ccflags += -msse2 +endif + CFLAGS_dcn_calcs.o := $(calcs_ccflags) CFLAGS_dcn_calc_auto.o := $(calcs_ccflags) CFLAGS_dcn_calc_math.o := $(calcs_ccflags) -Wno-tautological-compare --- a/drivers/gpu/drm/amd/display/dc/dcn20/Makefile +++ b/drivers/gpu/drm/amd/display/dc/dcn20/Makefile @@ -18,6 +18,10 @@ endif
CFLAGS_dcn20_resource.o := -mhard-float -msse $(cc_stack_align)
+ifdef CONFIG_CC_IS_CLANG +CFLAGS_dcn20_resource.o += -msse2 +endif + AMD_DAL_DCN20 = $(addprefix $(AMDDALPATH)/dc/dcn20/,$(DCN20))
AMD_DISPLAY_FILES += $(AMD_DAL_DCN20) --- a/drivers/gpu/drm/amd/display/dc/dml/Makefile +++ b/drivers/gpu/drm/amd/display/dc/dml/Makefile @@ -32,6 +32,10 @@ endif
dml_ccflags := -mhard-float -msse $(cc_stack_align)
+ifdef CONFIG_CC_IS_CLANG +dml_ccflags += -msse2 +endif + CFLAGS_display_mode_lib.o := $(dml_ccflags)
ifdef CONFIG_DRM_AMD_DC_DCN2_0 --- a/drivers/gpu/drm/amd/display/dc/dsc/Makefile +++ b/drivers/gpu/drm/amd/display/dc/dsc/Makefile @@ -9,6 +9,10 @@ endif
dsc_ccflags := -mhard-float -msse $(cc_stack_align)
+ifdef CONFIG_CC_IS_CLANG +dsc_ccflags += -msse2 +endif + CFLAGS_rc_calc.o := $(dsc_ccflags) CFLAGS_rc_calc_dpi.o := $(dsc_ccflags) CFLAGS_codec_main_amd.o := $(dsc_ccflags)