The armv6 uxt and sxt opcodes have a 2-bit rotate field which supports extractions from ofs = {0,8,16,24}. Special case ofs = 0, len <= 8 as AND.
Signed-off-by: Richard Henderson <richard.hender...@linaro.org> --- tcg/arm/tcg-target-has.h | 17 +++++++++++++ tcg/arm/tcg-target.c.inc | 54 +++++++++++++++++++++++++++++++++++----- 2 files changed, 65 insertions(+), 6 deletions(-) diff --git a/tcg/arm/tcg-target-has.h b/tcg/arm/tcg-target-has.h index 316185500d..d6ca35ed1a 100644 --- a/tcg/arm/tcg-target-has.h +++ b/tcg/arm/tcg-target-has.h @@ -82,4 +82,21 @@ extern bool use_neon_instructions; #define TCG_TARGET_HAS_cmpsel_vec 0 #define TCG_TARGET_HAS_tst_vec 1 +static inline bool +tcg_target_extract_valid(TCGType type, unsigned ofs, unsigned len) +{ + if (use_armv7_instructions) { + return true; /* SBFX or UBFX */ + } + switch (len) { + case 8: /* SXTB or UXTB */ + case 16: /* SXTH or UXTH */ + return (ofs % 8) == 0; + } + return false; +} + +#define TCG_TARGET_extract_valid tcg_target_extract_valid +#define TCG_TARGET_sextract_valid tcg_target_extract_valid + #endif diff --git a/tcg/arm/tcg-target.c.inc b/tcg/arm/tcg-target.c.inc index 9cfb733a14..12dad7307f 100644 --- a/tcg/arm/tcg-target.c.inc +++ b/tcg/arm/tcg-target.c.inc @@ -1036,19 +1036,61 @@ static void tcg_out_deposit(TCGContext *s, ARMCond cond, TCGReg rd, static void tcg_out_extract(TCGContext *s, ARMCond cond, TCGReg rd, TCGReg rn, int ofs, int len) { - /* ubfx */ - tcg_out32(s, 0x07e00050 | (cond << 28) | (rd << 12) | rn - | (ofs << 7) | ((len - 1) << 16)); + /* According to gcc, AND can be faster. */ + if (ofs == 0 && len <= 8) { + tcg_out_dat_imm(s, cond, ARITH_AND, rd, rn, + encode_imm_nofail((1 << len) - 1)); + return; + } + + if (use_armv7_instructions) { + /* ubfx */ + tcg_out32(s, 0x07e00050 | (cond << 28) | (rd << 12) | rn + | (ofs << 7) | ((len - 1) << 16)); + return; + } + + assert(ofs % 8 == 0); + switch (len) { + case 8: + /* uxtb */ + tcg_out32(s, 0x06ef0070 | (cond << 28) | (rd << 12) | (ofs << 7) | rn); + break; + case 16: + /* uxth */ + tcg_out32(s, 0x06ff0070 | (cond << 28) | (rd << 12) | (ofs << 7) | rn); + break; + default: + g_assert_not_reached(); + } } static void tcg_out_sextract(TCGContext *s, ARMCond cond, TCGReg rd, TCGReg rn, int ofs, int len) { - /* sbfx */ - tcg_out32(s, 0x07a00050 | (cond << 28) | (rd << 12) | rn - | (ofs << 7) | ((len - 1) << 16)); + if (use_armv7_instructions) { + /* sbfx */ + tcg_out32(s, 0x07a00050 | (cond << 28) | (rd << 12) | rn + | (ofs << 7) | ((len - 1) << 16)); + return; + } + + assert(ofs % 8 == 0); + switch (len) { + case 8: + /* sxtb */ + tcg_out32(s, 0x06af0070 | (cond << 28) | (rd << 12) | (ofs << 7) | rn); + break; + case 16: + /* sxth */ + tcg_out32(s, 0x06bf0070 | (cond << 28) | (rd << 12) | (ofs << 7) | rn); + break; + default: + g_assert_not_reached(); + } } + static void tcg_out_ld32u(TCGContext *s, ARMCond cond, TCGReg rd, TCGReg rn, int32_t offset) { -- 2.43.0