diff mbox series

[-next,v17,19/20] riscv: detect assembler support for .option arch

Message ID 20230327164941.20491-20-andy.chiu@sifive.com (mailing list archive)
State New, archived
Headers show
Series riscv: Add vector ISA support | expand

Commit Message

Andy Chiu March 27, 2023, 4:49 p.m. UTC 
Some extensions use .option arch directive to selectively enable certain
extensions in parts of its assembly code. For example, Zbb uses it to
inform assmebler to emit bit manipulation instructions. However,
supporting of this directive only exist on GNU assembler and has not
landed on clang at the moment, making TOOLCHAIN_HAS_ZBB depend on
AS_IS_GNU.

While it is still under review at https://reviews.llvm.org/D123515, the
upcoming Vector patch also requires this feature in assembler. Thus,
provide Kconfig AS_HAS_OPTION_ARCH to detect such feature. Then
TOOLCHAIN_HAS_XXX will be turned on automatically when the feature land.

Suggested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Andy Chiu <andy.chiu@sifive.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
---
 arch/riscv/Kconfig | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

Comments

Heiko Stuebner March 31, 2023, 1:33 p.m. UTC | #1 
Am Montag, 27. März 2023, 18:49:39 CEST schrieb Andy Chiu:
> Some extensions use .option arch directive to selectively enable certain
> extensions in parts of its assembly code. For example, Zbb uses it to
> inform assmebler to emit bit manipulation instructions. However,
> supporting of this directive only exist on GNU assembler and has not
> landed on clang at the moment, making TOOLCHAIN_HAS_ZBB depend on
> AS_IS_GNU.
> 
> While it is still under review at https://reviews.llvm.org/D123515, the
> upcoming Vector patch also requires this feature in assembler. Thus,
> provide Kconfig AS_HAS_OPTION_ARCH to detect such feature. Then
> TOOLCHAIN_HAS_XXX will be turned on automatically when the feature land.
> 
> Suggested-by: Nathan Chancellor <nathan@kernel.org>
> Signed-off-by: Andy Chiu <andy.chiu@sifive.com>
> Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
> Reviewed-by: Nathan Chancellor <nathan@kernel.org>

Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu>
Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu>
diff mbox series

Patch

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index d7252ced4ae6..91d5f2731f06 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -245,6 +245,12 @@  config RISCV_DMA_NONCOHERENT
 config AS_HAS_INSN
 	def_bool $(as-instr,.insn r 51$(comma) 0$(comma) 0$(comma) t0$(comma) t0$(comma) zero)
 
+config AS_HAS_OPTION_ARCH
+	# https://reviews.llvm.org/D123515
+	def_bool y
+	depends on $(as-instr, .option arch$(comma) +m)
+	depends on !$(as-instr, .option arch$(comma) -i)
+
 source "arch/riscv/Kconfig.socs"
 source "arch/riscv/Kconfig.errata"
 
@@ -443,7 +449,7 @@  config TOOLCHAIN_HAS_ZBB
 	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbb)
 	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbb)
 	depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900
-	depends on AS_IS_GNU
+	depends on AS_HAS_OPTION_ARCH
 
 config RISCV_ISA_ZBB
 	bool "Zbb extension support for bit manipulation instructions"