Re: [Qemu-devel] [PATCH v3 5/6] Do constant folding for shift operations.

[Blue Swirl]

On Sat, Jul 30, 2011 at 3:25 PM, Blue Swirl <address@hidden> wrote:
> On Thu, Jul 7, 2011 at 3:37 PM, Kirill Batuzov <address@hidden> wrote:
>> Perform constant forlding for SHR, SHL, SAR, ROTR, ROTL operations.
>
> This patch broke build on targets (Sparc, MIPS) which don't implement
> rotation ops, the next patch likewise. I committed a fix.

Unfortunately my patch which fixed Sparc build broke i386 build, so I
committed another fix.

>> Signed-off-by: Kirill Batuzov <address@hidden>
>> ---
>>  tcg/optimize.c |   72 
>> ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>>  1 files changed, 72 insertions(+), 0 deletions(-)
>>
>> diff --git a/tcg/optimize.c b/tcg/optimize.c
>> index c469952..a1bb287 100644
>> --- a/tcg/optimize.c
>> +++ b/tcg/optimize.c
>> @@ -102,6 +102,11 @@ static int op_bits(int op)
>>     case INDEX_op_and_i32:
>>     case INDEX_op_or_i32:
>>     case INDEX_op_xor_i32:
>> +    case INDEX_op_shl_i32:
>> +    case INDEX_op_shr_i32:
>> +    case INDEX_op_sar_i32:
>> +    case INDEX_op_rotl_i32:
>> +    case INDEX_op_rotr_i32:
>>         return 32;
>>  #if TCG_TARGET_REG_BITS == 64
>>     case INDEX_op_mov_i64:
>> @@ -111,6 +116,11 @@ static int op_bits(int op)
>>     case INDEX_op_and_i64:
>>     case INDEX_op_or_i64:
>>     case INDEX_op_xor_i64:
>> +    case INDEX_op_shl_i64:
>> +    case INDEX_op_shr_i64:
>> +    case INDEX_op_sar_i64:
>> +    case INDEX_op_rotl_i64:
>> +    case INDEX_op_rotr_i64:
>>         return 64;
>>  #endif
>>     default:
>> @@ -205,6 +215,58 @@ static TCGArg do_constant_folding_2(int op, TCGArg x, 
>> TCGArg y)
>>     CASE_OP_32_64(xor):
>>         return x ^ y;
>>
>> +    case INDEX_op_shl_i32:
>> +        return (uint32_t)x << (uint32_t)y;
>> +
>> +#if TCG_TARGET_REG_BITS == 64
>> +    case INDEX_op_shl_i64:
>> +        return (uint64_t)x << (uint64_t)y;
>> +#endif
>> +
>> +    case INDEX_op_shr_i32:
>> +        return (uint32_t)x >> (uint32_t)y;
>> +
>> +#if TCG_TARGET_REG_BITS == 64
>> +    case INDEX_op_shr_i64:
>> +        return (uint64_t)x >> (uint64_t)y;
>> +#endif
>> +
>> +    case INDEX_op_sar_i32:
>> +        return (int32_t)x >> (int32_t)y;
>> +
>> +#if TCG_TARGET_REG_BITS == 64
>> +    case INDEX_op_sar_i64:
>> +        return (int64_t)x >> (int64_t)y;
>> +#endif
>> +
>> +    case INDEX_op_rotr_i32:
>> +#if TCG_TARGET_REG_BITS == 64
>> +        x &= 0xffffffff;
>> +        y &= 0xffffffff;
>> +#endif
>> +        x = (x << (32 - y)) | (x >> y);
>> +        return x;
>> +
>> +#if TCG_TARGET_REG_BITS == 64
>> +    case INDEX_op_rotr_i64:
>> +        x = (x << (64 - y)) | (x >> y);
>> +        return x;
>> +#endif
>> +
>> +    case INDEX_op_rotl_i32:
>> +#if TCG_TARGET_REG_BITS == 64
>> +        x &= 0xffffffff;
>> +        y &= 0xffffffff;
>> +#endif
>> +        x = (x << y) | (x >> (32 - y));
>> +        return x;
>> +
>> +#if TCG_TARGET_REG_BITS == 64
>> +    case INDEX_op_rotl_i64:
>> +        x = (x << y) | (x >> (64 - y));
>> +        return x;
>> +#endif
>> +
>>     default:
>>         fprintf(stderr,
>>                 "Unrecognized operation %d in do_constant_folding.\n", op);
>> @@ -278,6 +340,11 @@ static TCGArg *tcg_constant_folding(TCGContext *s, 
>> uint16_t *tcg_opc_ptr,
>>         switch (op) {
>>         CASE_OP_32_64(add):
>>         CASE_OP_32_64(sub):
>> +        CASE_OP_32_64(shl):
>> +        CASE_OP_32_64(shr):
>> +        CASE_OP_32_64(sar):
>> +        CASE_OP_32_64(rotl):
>> +        CASE_OP_32_64(rotr):
>>             if (temps[args[1]].state == TCG_TEMP_CONST) {
>>                 /* Proceed with possible constant folding. */
>>                 break;
>> @@ -363,6 +430,11 @@ static TCGArg *tcg_constant_folding(TCGContext *s, 
>> uint16_t *tcg_opc_ptr,
>>         CASE_OP_32_64(or):
>>         CASE_OP_32_64(and):
>>         CASE_OP_32_64(xor):
>> +        CASE_OP_32_64(shl):
>> +        CASE_OP_32_64(shr):
>> +        CASE_OP_32_64(sar):
>> +        CASE_OP_32_64(rotl):
>> +        CASE_OP_32_64(rotr):
>>             if (temps[args[1]].state == TCG_TEMP_CONST
>>                 && temps[args[2]].state == TCG_TEMP_CONST) {
>>                 gen_opc_buf[op_index] = op_to_movi(op);
>> --
>> 1.7.4.1
>>
>>
>>
>