From: Nick Desaulniers ndesaulniers@google.com
[ Upstream commit 0f0727d971f6fdf8f1077180d495ddb9928f0c8b ]
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: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/amd/display/dc/calcs/Makefile | 4 ++++ drivers/gpu/drm/amd/display/dc/dml/Makefile | 4 ++++ 2 files changed, 8 insertions(+)
diff --git a/drivers/gpu/drm/amd/display/dc/calcs/Makefile b/drivers/gpu/drm/amd/display/dc/calcs/Makefile index 95f332ee3e7e6..16614d73a5fcf 100644 --- 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 diff --git a/drivers/gpu/drm/amd/display/dc/dml/Makefile b/drivers/gpu/drm/amd/display/dc/dml/Makefile index d97ca6528f9d9..934ffe1b4b00e 100644 --- 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) CFLAGS_display_pipe_clocks.o := $(dml_ccflags) CFLAGS_dml1_display_rq_dlg_calc.o := $(dml_ccflags)