Thread (63 messages) 63 messages, 11 authors, 2017-11-09

[PATCH 07/15] arm64: use -mno-implicit-float instead of -mgeneral-regs-only

From: Nick Desaulniers <hidden>
Date: 2017-11-03 17:50:12
Also in: lkml

I think this bug was fixed upstream in LLVM.  Do we still want to take
this workaround?

On Fri, Nov 3, 2017 at 10:11 AM, Sami Tolvanen [off-list ref] wrote:
quoted hunk ↗ jump to hunk
From: Greg Hackmann <redacted>

LLVM bug 30792 causes clang's AArch64 backend to crash compiling
arch/arm64/crypto/aes-ce-cipher.c.  Replacing -mgeneral-regs-only with
-mno-implicit-float is the suggested workaround.

Signed-off-by: Greg Hackmann <redacted>
Cc: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
---
 arch/arm64/Makefile | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
index 939b310913cf..eb6f3c9ec6cb 100644
--- a/arch/arm64/Makefile
+++ b/arch/arm64/Makefile
@@ -45,7 +45,13 @@ $(warning Detected assembler with broken .inst; disassembly will be unreliable)
   endif
 endif

-KBUILD_CFLAGS  += -mgeneral-regs-only $(lseinstr) $(brokengasinst)
+ifeq ($(cc-name),clang)
+# This is a workaround for https://bugs.llvm.org/show_bug.cgi?id=30792.
+KBUILD_CFLAGS  += -mno-implicit-float
+else
+KBUILD_CFLAGS  += -mgeneral-regs-only
+endif
+KBUILD_CFLAGS  += $(lseinstr) $(brokengasinst)
 KBUILD_CFLAGS  += -fno-asynchronous-unwind-tables
 KBUILD_CFLAGS  += $(call cc-option, -mpc-relative-literal-loads)
 KBUILD_AFLAGS  += $(lseinstr) $(brokengasinst)
--
2.15.0.403.gc27cc4dac6-goog


-- 
Thanks,
~Nick Desaulniers
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