From e2e7168a214b0ed98dc357bba96816486a289762 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Sun, 30 Aug 2020 08:57:20 -0700 Subject: [PATCH] tcg: Adjust simd_desc size encoding MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit With larger vector sizes, it turns out oprsz == maxsz, and we only need to represent mismatch for oprsz <= 32. We do, however, need to represent larger oprsz and do so without reducing SIMD_DATA_BITS. Reduce the size of the oprsz field and increase the maxsz field. Steal the oprsz value of 24 to indicate equality with maxsz. Tested-by: Frank Chang Reviewed-by: Frank Chang Reviewed-by: Philippe Mathieu-Daudé Signed-off-by: Richard Henderson --- include/tcg/tcg-gvec-desc.h | 38 ++++++++++++++++++++++++------------- tcg/tcg-op-gvec.c | 35 ++++++++++++++++++++++++++-------- 2 files changed, 52 insertions(+), 21 deletions(-) diff --git a/include/tcg/tcg-gvec-desc.h b/include/tcg/tcg-gvec-desc.h index 0224ac3e78..704bd86454 100644 --- a/include/tcg/tcg-gvec-desc.h +++ b/include/tcg/tcg-gvec-desc.h @@ -20,29 +20,41 @@ #ifndef TCG_TCG_GVEC_DESC_H #define TCG_TCG_GVEC_DESC_H -/* ??? These bit widths are set for ARM SVE, maxing out at 256 byte vectors. */ -#define SIMD_OPRSZ_SHIFT 0 -#define SIMD_OPRSZ_BITS 5 +/* + * This configuration allows MAXSZ to represent 2048 bytes, and + * OPRSZ to match MAXSZ, or represent the smaller values 8, 16, or 32. + * + * Encode this with: + * 0, 1, 3 -> 8, 16, 32 + * 2 -> maxsz + * + * This steals the input that would otherwise map to 24 to match maxsz. + */ +#define SIMD_MAXSZ_SHIFT 0 +#define SIMD_MAXSZ_BITS 8 -#define SIMD_MAXSZ_SHIFT (SIMD_OPRSZ_SHIFT + SIMD_OPRSZ_BITS) -#define SIMD_MAXSZ_BITS 5 +#define SIMD_OPRSZ_SHIFT (SIMD_MAXSZ_SHIFT + SIMD_MAXSZ_BITS) +#define SIMD_OPRSZ_BITS 2 -#define SIMD_DATA_SHIFT (SIMD_MAXSZ_SHIFT + SIMD_MAXSZ_BITS) +#define SIMD_DATA_SHIFT (SIMD_OPRSZ_SHIFT + SIMD_OPRSZ_BITS) #define SIMD_DATA_BITS (32 - SIMD_DATA_SHIFT) /* Create a descriptor from components. */ uint32_t simd_desc(uint32_t oprsz, uint32_t maxsz, int32_t data); -/* Extract the operation size from a descriptor. */ -static inline intptr_t simd_oprsz(uint32_t desc) -{ - return (extract32(desc, SIMD_OPRSZ_SHIFT, SIMD_OPRSZ_BITS) + 1) * 8; -} - /* Extract the max vector size from a descriptor. */ static inline intptr_t simd_maxsz(uint32_t desc) { - return (extract32(desc, SIMD_MAXSZ_SHIFT, SIMD_MAXSZ_BITS) + 1) * 8; + return extract32(desc, SIMD_MAXSZ_SHIFT, SIMD_MAXSZ_BITS) * 8 + 8; +} + +/* Extract the operation size from a descriptor. */ +static inline intptr_t simd_oprsz(uint32_t desc) +{ + uint32_t f = extract32(desc, SIMD_OPRSZ_SHIFT, SIMD_OPRSZ_BITS); + intptr_t o = f * 8 + 8; + intptr_t m = simd_maxsz(desc); + return f == 2 ? m : o; } /* Extract the operation-specific data from a descriptor. */ diff --git a/tcg/tcg-op-gvec.c b/tcg/tcg-op-gvec.c index 7ebd9e8298..ddbe06b71a 100644 --- a/tcg/tcg-op-gvec.c +++ b/tcg/tcg-op-gvec.c @@ -37,11 +37,21 @@ static const TCGOpcode vecop_list_empty[1] = { 0 }; of the operand offsets so that we can check them all at once. */ static void check_size_align(uint32_t oprsz, uint32_t maxsz, uint32_t ofs) { - uint32_t opr_align = oprsz >= 16 ? 15 : 7; - uint32_t max_align = maxsz >= 16 || oprsz >= 16 ? 15 : 7; - tcg_debug_assert(oprsz > 0); - tcg_debug_assert(oprsz <= maxsz); - tcg_debug_assert((oprsz & opr_align) == 0); + uint32_t max_align; + + switch (oprsz) { + case 8: + case 16: + case 32: + tcg_debug_assert(oprsz <= maxsz); + break; + default: + tcg_debug_assert(oprsz == maxsz); + break; + } + tcg_debug_assert(maxsz <= (8 << SIMD_MAXSZ_BITS)); + + max_align = maxsz >= 16 ? 15 : 7; tcg_debug_assert((maxsz & max_align) == 0); tcg_debug_assert((ofs & max_align) == 0); } @@ -77,12 +87,21 @@ uint32_t simd_desc(uint32_t oprsz, uint32_t maxsz, int32_t data) { uint32_t desc = 0; - assert(oprsz % 8 == 0 && oprsz <= (8 << SIMD_OPRSZ_BITS)); - assert(maxsz % 8 == 0 && maxsz <= (8 << SIMD_MAXSZ_BITS)); - assert(data == sextract32(data, 0, SIMD_DATA_BITS)); + check_size_align(oprsz, maxsz, 0); + tcg_debug_assert(data == sextract32(data, 0, SIMD_DATA_BITS)); oprsz = (oprsz / 8) - 1; maxsz = (maxsz / 8) - 1; + + /* + * We have just asserted in check_size_align that either + * oprsz is {8,16,32} or matches maxsz. Encode the final + * case with '2', as that would otherwise map to 24. + */ + if (oprsz == maxsz) { + oprsz = 2; + } + desc = deposit32(desc, SIMD_OPRSZ_SHIFT, SIMD_OPRSZ_BITS, oprsz); desc = deposit32(desc, SIMD_MAXSZ_SHIFT, SIMD_MAXSZ_BITS, maxsz); desc = deposit32(desc, SIMD_DATA_SHIFT, SIMD_DATA_BITS, data);