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Re: [Qemu-devel] [PATCH 09/12] tcg-s390: Use risbgz for andi
From: |
Paolo Bonzini |
Subject: |
Re: [Qemu-devel] [PATCH 09/12] tcg-s390: Use risbgz for andi |
Date: |
Wed, 27 Mar 2013 20:03:35 +0100 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130311 Thunderbird/17.0.4 |
Il 27/03/2013 19:52, Richard Henderson ha scritto:
> This is immediately usable by the tlb lookup code.
>
> Signed-off-by: Richard Henderson <address@hidden>
> ---
> tcg/s390/tcg-target.c | 58
> ++++++++++++++++++++++++++++++++++++++++++++++-----
> 1 file changed, 53 insertions(+), 5 deletions(-)
>
> diff --git a/tcg/s390/tcg-target.c b/tcg/s390/tcg-target.c
> index 203cbb5..2bab245 100644
> --- a/tcg/s390/tcg-target.c
> +++ b/tcg/s390/tcg-target.c
> @@ -827,6 +827,15 @@ static void tcg_out_ld_abs(TCGContext *s, TCGType type,
> TCGReg dest, void *abs)
> tcg_out_ld(s, type, dest, dest, addr & 0xffff);
> }
>
> +static inline void tcg_out_risbg(TCGContext *s, TCGReg dest, TCGReg src,
> + int msb, int lsb, int ofs, int z)
> +{
> + /* Format RIE-f */
> + tcg_out16(s, (RIE_RISBG & 0xff00) | (dest << 4) | src);
> + tcg_out16(s, (msb << 8) | (z << 7) | lsb);
> + tcg_out16(s, (ofs << 8) | (RIE_RISBG & 0xff));
> +}
> +
> static void tgen_ext8s(TCGContext *s, TCGType type, TCGReg dest, TCGReg src)
> {
> if (facilities & FACILITY_EXT_IMM) {
> @@ -940,6 +949,36 @@ static inline void tgen64_addi(TCGContext *s, TCGReg
> dest, int64_t val)
>
> }
>
> +/* Accept bit patterns like these:
> + 0....01....1
> + 1....10....0
> + 1..10..01..1
> + 0..01..10..0
> + Copied from gcc sources. */
> +static inline bool risbg_mask(uint64_t c)
> +{
> + uint64_t lsb;
> + /* We don't change the number of transitions by inverting,
> + so make sure we start with the LSB zero. */
> + if (c & 1) {
> + c = ~c;
> + }
> + /* Reject all zeros or all ones. */
> + if (c == 0) {
> + return false;
> + }
> + /* Find the first transition. */
> + lsb = c & -c;
> + /* Invert to look for a second transition. */
> + c = ~c;
> + /* Erase the first transition. */
> + c &= -lsb;
> + /* Find the second transition, if any. */
> + lsb = c & -c;
> + /* Match if all the bits are 1's, or if c is zero. */
> + return c == -lsb;
> +}
> +
> static void tgen_andi(TCGContext *s, TCGType type, TCGReg dest, uint64_t val)
> {
> static const S390Opcode ni_insns[4] = {
> @@ -986,6 +1025,19 @@ static void tgen_andi(TCGContext *s, TCGType type,
> TCGReg dest, uint64_t val)
> }
> }
> }
> + if ((facilities & FACILITY_GEN_INST_EXT) && risbg_mask(val)) {
> + int msb, lsb;
> + if ((val & 0x8000000000000001ull) == 0x8000000000000001ull) {
> + /* Achieve wraparound by swapping msb and lsb. */
> + msb = 63 - ctz64(~val);
> + lsb = clz64(~val) + 1;
> + } else {
> + msb = clz64(val);
> + lsb = 63 - ctz64(val);
> + }
> + tcg_out_risbg(s, dest, dest, msb, lsb, 0, 1);
> + return;
> + }
>
> /* Fall back to loading the constant. */
> tcg_out_movi(s, type, TCG_TMP0, val);
> @@ -1142,11 +1194,7 @@ static void tgen_deposit(TCGContext *s, TCGReg dest,
> TCGReg src,
> {
> int lsb = (63 - ofs);
> int msb = lsb - (len - 1);
> -
> - /* Format RIE-f */
> - tcg_out16(s, (RIE_RISBG & 0xff00) | (dest << 4) | src);
> - tcg_out16(s, (msb << 8) | lsb);
> - tcg_out16(s, (ofs << 8) | (RIE_RISBG & 0xff));
> + tcg_out_risbg(s, dest, src, msb, lsb, ofs, 0);
> }
>
> static void tgen_gotoi(TCGContext *s, int cc, tcg_target_long dest)
>
I wonder if PPC can use this too.
Paolo
- [Qemu-devel] [PATCH 03/12] tcg-s390: Remove useless preprocessor conditions, (continued)
- [Qemu-devel] [PATCH 03/12] tcg-s390: Remove useless preprocessor conditions, Richard Henderson, 2013/03/27
- [Qemu-devel] [PATCH 04/12] tcg-s390: Implement add2/sub2 opcodes, Richard Henderson, 2013/03/27
- [Qemu-devel] [PATCH 05/12] tcg-s390: Implement mulu2_i64 opcode, Richard Henderson, 2013/03/27
- [Qemu-devel] [PATCH 06/12] tcg-s390: Implement movcond opcodes, Richard Henderson, 2013/03/27
- [Qemu-devel] [PATCH 07/12] tcg-s390: Implement deposit opcodes, Richard Henderson, 2013/03/27
- [Qemu-devel] [PATCH 08/12] tcg-s390: Remove constraint letters for and, Richard Henderson, 2013/03/27
- [Qemu-devel] [PATCH 10/12] tcg-s390: Cleanup argument shuffling fixme in softmmu code, Richard Henderson, 2013/03/27
- [Qemu-devel] [PATCH 09/12] tcg-s390: Use risbgz for andi, Richard Henderson, 2013/03/27
- Re: [Qemu-devel] [PATCH 09/12] tcg-s390: Use risbgz for andi,
Paolo Bonzini <=
- [Qemu-devel] [PATCH 12/12] tcg-s390: Use all 20 bits of the offset in tcg_out_mem, Richard Henderson, 2013/03/27
- [Qemu-devel] [PATCH 11/12] tcg-s390: Use load-address for addition, Richard Henderson, 2013/03/27