| From 8dec306952f017f41ab8f64e9db2d073aaaebf86 Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Mon, 22 Jul 2019 15:31:05 -0700 |
| Subject: drm/amd/display: readd -msse2 to prevent Clang from emitting libcalls |
| to undefined SW FP routines |
| |
| 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) |
| -- |
| 2.20.1 |
| |