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powerpc/64s: Disable pcrel code model on Clang

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Clang has a bug that casues the pcrel code model not to be used when any of
-msoft-float, -mno-altivec, or -mno-vsx are set. Leaving these off causes
FP/vector instructions to be generated, causing crashes. So disable pcrel
for clang for now.

Fixes: 7e3a68be42 ("powerpc/64: vmlinux support building with PCREL addresing")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230426055848.402993-3-npiggin@gmail.com
This commit is contained in:
Nicholas Piggin 2023-04-26 15:58:39 +10:00 committed by Michael Ellerman
parent 0c993300d5
commit 169f899796
1 changed files with 6 additions and 1 deletions
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7
arch/powerpc/Kconfig
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@ -8,7 +8,12 @@ config CC_HAS_PREFIXED
def_bool PPC64 && $(cc-option, -mcpu=power10 -mprefixed)
config CC_HAS_PCREL
def_bool PPC64 && $(cc-option, -mcpu=power10 -mpcrel)
# Clang has a bug (https://github.com/llvm/llvm-project/issues/62372)
# where pcrel code is not generated if -msoft-float, -mno-altivec, or
# -mno-vsx options are also given. Without these options, fp/vec
# instructions are generated from regular kernel code. So Clang can't
# do pcrel yet.
def_bool PPC64 && CC_IS_GCC && $(cc-option, -mcpu=power10 -mpcrel)
config 32BIT
bool