From bbed332c7ad12e9885d3f457f366fa0b29445dcd Mon Sep 17 00:00:00 2001 From: Aurelien Jarno Date: Thu, 6 Sep 2012 16:47:14 +0200 Subject: [PATCH] tcg/optimize: simplify shift/rot r, 0, a => movi r, 0 cases shift/rot r, 0, a is equivalent to movi r, 0. Reviewed-by: Richard Henderson Signed-off-by: Aurelien Jarno Signed-off-by: Michael Roth --- tcg/optimize.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/tcg/optimize.c b/tcg/optimize.c index c12cb2b..1698ba3 100644 --- a/tcg/optimize.c +++ b/tcg/optimize.c @@ -322,6 +322,26 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr, break; } + /* Simplify expressions for "shift/rot r, 0, a => movi r, 0" */ + switch (op) { + 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[1]].val == 0) { + gen_opc_buf[op_index] = op_to_movi(op); + tcg_opt_gen_movi(gen_args, args[0], 0, nb_temps, nb_globals); + args += 3; + gen_args += 2; + continue; + } + break; + default: + break; + } + /* Simplify expression for "op r, a, 0 => mov r, a" cases */ switch (op) { CASE_OP_32_64(add): -- 1.8.0.2