mirror of https://github.com/xemu-project/xemu.git
df4252b2ec
We're going to make changes that will required each helper to be responsible for the 'vstart' management, i.e. we will relieve the 'vstart < vl' assumption that helpers have today. Helpers are usually able to deal with vstart >= vl, i.e. doing nothing aside from setting vstart = 0 at the end, but the tail update functions will update the tail regardless of vstart being valid or not. Unifying the tail update process in a single function that would handle the vstart >= vl case isn't trivial (see [1] for more info). This patch takes a blunt approach: do an early exit in every single vector helper if vstart >= vl, unless the helper is guarded with vstart_eq_zero in the translation. For those cases the helper is ready to deal with cases where vl might be zero, i.e. throwing exceptions based on it like vcpop_m() and first_m(). Helpers that weren't changed: - vcpop_m(), vfirst_m(), vmsetm(), GEN_VEXT_VIOTA_M(): these are guarded directly with vstart_eq_zero; - GEN_VEXT_VCOMPRESS_VM(): guarded with vcompress_vm_check() that checks vstart_eq_zero; - GEN_VEXT_RED(): guarded with either reduction_check() or reduction_widen_check(), both check vstart_eq_zero; - GEN_VEXT_FRED(): guarded with either freduction_check() or freduction_widen_check(), both check vstart_eq_zero. Another exception is vext_ldst_whole(), who operates on effective vector length regardless of the current settings in vtype and vl. [1] https://lore.kernel.org/qemu-riscv/1590234b-0291-432a-a0fa-c5a6876097bc@linux.alibaba.com/ Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com> Acked-by: Alistair Francis <alistair.francis@wdc.com> Message-ID: <20240314175704.478276-7-dbarboza@ventanamicro.com> Signed-off-by: Alistair Francis <alistair.francis@wdc.com> |
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| cris | ||
| hexagon | ||
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| i386 | ||
| loongarch | ||
| m68k | ||
| microblaze | ||
| mips | ||
| nios2 | ||
| openrisc | ||
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| riscv | ||
| rx | ||
| s390x | ||
| sh4 | ||
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| tricore | ||
| xtensa | ||
| Kconfig | ||
| meson.build | ||
| target-common.c | ||