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| author | Richard Henderson <rth@twiddle.net> | 2014-01-31 07:42:11 -0600 |
|---|---|---|
| committer | Richard Henderson <rth@twiddle.net> | 2014-02-17 10:12:29 -0600 |
| commit | 464a1441c138b4f29cff26d406298661e588235b (patch) | |
| tree | 452c0888133591fc0cf06b905e143b28bf62a573 /tcg | |
| parent | e64e958e202c563730159c52f7c9116c80ceca52 (diff) | |
| download | qemu-464a1441c138b4f29cff26d406298661e588235b.tar.gz | |
tcg/optimize: Add more identity simplifications
Recognize 0 operand to andc, and -1 operands to and, orc, eqv.
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Diffstat (limited to 'tcg')
| -rw-r--r-- | tcg/optimize.c | 39 |
1 files changed, 24 insertions, 15 deletions
diff --git a/tcg/optimize.c b/tcg/optimize.c index c1b9284600..7777743e88 100644 --- a/tcg/optimize.c +++ b/tcg/optimize.c @@ -716,7 +716,7 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr, break; } - /* Simplify expression for "op r, a, 0 => mov r, a" cases */ + /* Simplify expression for "op r, a, const => mov r, a" cases */ switch (op) { CASE_OP_32_64(add): CASE_OP_32_64(sub): @@ -727,23 +727,32 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr, CASE_OP_32_64(rotr): CASE_OP_32_64(or): CASE_OP_32_64(xor): - if (temps[args[1]].state == TCG_TEMP_CONST) { - /* Proceed with possible constant folding. */ - break; - } - if (temps[args[2]].state == TCG_TEMP_CONST + CASE_OP_32_64(andc): + if (temps[args[1]].state != TCG_TEMP_CONST + && temps[args[2]].state == TCG_TEMP_CONST && temps[args[2]].val == 0) { - if (temps_are_copies(args[0], args[1])) { - s->gen_opc_buf[op_index] = INDEX_op_nop; - } else { - s->gen_opc_buf[op_index] = op_to_mov(op); - tcg_opt_gen_mov(s, gen_args, args[0], args[1]); - gen_args += 2; - } - args += 3; - continue; + goto do_mov3; } break; + CASE_OP_32_64(and): + CASE_OP_32_64(orc): + CASE_OP_32_64(eqv): + if (temps[args[1]].state != TCG_TEMP_CONST + && temps[args[2]].state == TCG_TEMP_CONST + && temps[args[2]].val == -1) { + goto do_mov3; + } + break; + do_mov3: + if (temps_are_copies(args[0], args[1])) { + s->gen_opc_buf[op_index] = INDEX_op_nop; + } else { + s->gen_opc_buf[op_index] = op_to_mov(op); + tcg_opt_gen_mov(s, gen_args, args[0], args[1]); + gen_args += 2; + } + args += 3; + continue; default: break; } |