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authorRĂ©mi Denis-Courmont <remi@remlab.net>2022-10-05 19:12:54 +0300
committerLynne <dev@lynne.ee>2022-10-10 02:22:12 +0200
commitf59a767ccd56ba1b82ae94e2229f9151936f8b7c (patch)
treee8bdb02a278a3895ca6e5db1e4dc1a89fce28069 /libavutil
parent8009581912d0e5d6ecfa650cd0ce90c58c515b69 (diff)
lavu/riscv: helper macro for VTYPE encoding
On most cases, the vector type (VTYPE) for the RISC-V Vector extension is supplied as an immediate value, with either of the VSETVLI or VSETIVLI instructions. There is however a third instruction VSETVL which takes the vector type from a general purpose register. That is so the type can be selected at run-time. This introduces a macro to load a (valid) vector type into a register. The syntax follows that of VSETVLI and VSETIVLI, with element size, group multiplier, then tail and mask policies.
Diffstat (limited to 'libavutil')
-rw-r--r--libavutil/riscv/asm.S75
1 files changed, 75 insertions, 0 deletions
diff --git a/libavutil/riscv/asm.S b/libavutil/riscv/asm.S
index ffa0bd9068..6ca74f263a 100644
--- a/libavutil/riscv/asm.S
+++ b/libavutil/riscv/asm.S
@@ -92,3 +92,78 @@
shnadd 3, \rd, \rs1, \rs2
.endm
#endif
+
+ /* Convenience macro to load a Vector type (vtype) as immediate */
+ .macro lvtypei rd, e, m=m1, tp=tu, mp=mu
+
+ .ifc \e,e8
+ .equ ei, 0
+ .else
+ .ifc \e,e16
+ .equ ei, 8
+ .else
+ .ifc \e,e32
+ .equ ei, 16
+ .else
+ .ifc \e,e64
+ .equ ei, 24
+ .else
+ .error "Unknown element type"
+ .endif
+ .endif
+ .endif
+ .endif
+
+ .ifc \m,m1
+ .equ mi, 0
+ .else
+ .ifc \m,m2
+ .equ mi, 1
+ .else
+ .ifc \m,m4
+ .equ mi, 2
+ .else
+ .ifc \m,m8
+ .equ mi, 3
+ .else
+ .ifc \m,mf8
+ .equ mi, 5
+ .else
+ .ifc \m,mf4
+ .equ mi, 6
+ .else
+ .ifc \m,mf2
+ .equ mi, 7
+ .else
+ .error "Unknown multiplier"
+ .equ mi, 3
+ .endif
+ .endif
+ .endif
+ .endif
+ .endif
+ .endif
+ .endif
+
+ .ifc \tp,tu
+ .equ tpi, 0
+ .else
+ .ifc \tp,ta
+ .equ tpi, 64
+ .else
+ .error "Unknown tail policy"
+ .endif
+ .endif
+
+ .ifc \mp,mu
+ .equ mpi, 0
+ .else
+ .ifc \mp,ma
+ .equ mpi, 128
+ .else
+ .error "Unknown mask policy"
+ .endif
+ .endif
+
+ li \rd, (ei | mi | tpi | mpi)
+ .endm