On 07/31/2016 10:43 AM, Benjamin Herrenschmidt wrote:
Translate most conditions to TCG conditions and avoid the helper
for most of the common cases.
Signed-off-by: Benjamin Herrenschmidt <b...@kernel.crashing.org>
---
target-ppc/translate.c | 168 ++++++++++++++++++++++++++++++++++++++-----------
1 file changed, 132 insertions(+), 36 deletions(-)
diff --git a/target-ppc/translate.c b/target-ppc/translate.c
index 47eb9ed..561976f 100644
--- a/target-ppc/translate.c
+++ b/target-ppc/translate.c
@@ -3639,82 +3639,178 @@ static void gen_sc(DisasContext *ctx)
/*** Trap ***/
-/* Check for unconditional traps (always or never) */
-static bool check_unconditional_trap(DisasContext *ctx)
+static int TO2tcg[32] = {
Should be const.
+ -1, /* 0x0f > or = or u> or u< */
+ -1, /* 0x13 < or u< or u> -> weird */
+ -1, /* 0x19 < or > or u> -> weird */
+ -1, /* 0x1a < or > or u< -> weird */
+ -1, /* 0x1b < or > or u> or u< -> weird */
Not that it matters much, but when you have both < and >, or both u< and u>,
you can collapse to NE, no matter what else is there.
+#define TRAP_UNCOND (-1)
+#define TRAP_HELPER (-2)
+
+static int precheck_trap(DisasContext *ctx)
{
- /* Trap never */
- if (TO(ctx->opcode) == 0) {
- return true;
+ int cond = TO2tcg[TO(ctx->opcode)];
+
+ /* Weird traps go to helper */
+ if (cond < 0) {
+ return TRAP_HELPER;
}
- /* Trap always */
- if (TO(ctx->opcode) == 31) {
+ /* Unconditionals */
+ if (cond == TCG_COND_ALWAYS) {
gen_exception_err(ctx, POWERPC_EXCP_PROGRAM, POWERPC_EXCP_TRAP);
- return true;
+ return TRAP_UNCOND;
}
- return false;
+ if (cond == TCG_COND_NEVER) {
+ return TRAP_UNCOND;
+ }
+ /* Invert the condition as we branch over the exception when the
+ * condition is *not* met
+ */
+ return tcg_invert_cond(cond);
+}
+
+static void gen_trap(DisasContext *ctx)
+{
+ TCGv_i32 t0, t1;
+
+ t0 = tcg_const_i32(POWERPC_EXCP_PROGRAM);
+ t1 = tcg_const_i32(POWERPC_EXCP_TRAP);
+ gen_update_nip(ctx, ctx->nip - 4);
+ gen_helper_raise_exception_err(cpu_env, t0, t1);
gen_exception_err, as with the unconditional trap?
static void gen_tw(DisasContext *ctx)
{
- TCGv_i32 t0;
+ int cond = precheck_trap(ctx);
+ TCGLabel *l1;
+ TCGv t0;
+ TCGv t1;
- if (check_unconditional_trap(ctx)) {
+ if (cond == TRAP_UNCOND) {
+ return;
+ } else if (cond == TRAP_HELPER) {
+ TCGv_i32 trapop = tcg_const_i32(TO(ctx->opcode));
+ gen_helper_tw(cpu_env, cpu_gpr[rA(ctx->opcode)],
+ cpu_gpr[rB(ctx->opcode)], trapop);
+ tcg_temp_free_i32(trapop);
return;
}
- t0 = tcg_const_i32(TO(ctx->opcode));
- gen_helper_tw(cpu_env, cpu_gpr[rA(ctx->opcode)], cpu_gpr[rB(ctx->opcode)],
- t0);
- tcg_temp_free_i32(t0);
+ l1 = gen_new_label();
+ t0 = tcg_temp_new();
+ t1 = tcg_temp_new();
+ tcg_gen_ext32s_tl(t0, cpu_gpr[rA(ctx->opcode)]);
+ tcg_gen_ext32s_tl(t1, cpu_gpr[rB(ctx->opcode)]);
+ tcg_gen_brcond_tl(cond, t0, t1, l1);
It's just as easy, and perhaps better, to truncate to 32 bits instead of
extending to TL bits.
r~
