Hi all,
If we want to add more macro fusion cases in the arm backend we need to rework
the aarch_macro_fusion_pair_p a bit
to not return early during the MOVW/MOVT fusion checks. This simple patch does
that by adding a helper function
that can be called with the two sets to check if they satisfy the fusion logic.
There is no change in codegen.
Bootstrapped and tested on arm-none-linux-gnueabihf.
Ok for trunk?
Thanks,
Kyrill
2016-08-23 Kyrylo Tkachov <kyrylo.tkac...@arm.com>
* config/arm/arm.c (arm_sets_movw_movt_fusible_p): New function.
(aarch_macro_fusion_pair_p): Use above to avoid early return.
diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
index 2deb62b2f724ef9c17f585046480e47abcd341b0..bb6ada9e0f62efae95fdeb11dfcee14dba3299b0 100644
--- a/gcc/config/arm/arm.c
+++ b/gcc/config/arm/arm.c
@@ -29903,11 +29903,57 @@ arm_macro_fusion_p (void)
return current_tune->fusible_ops != tune_params::FUSE_NOTHING;
}
+/* Return true if the two back-to-back sets PREV_SET, CURR_SET are suitable
+ for MOVW / MOVT macro fusion. */
+
+static bool
+arm_sets_movw_movt_fusible_p (rtx prev_set, rtx curr_set)
+{
+ /* We are trying to fuse
+ movw imm / movt imm
+ instructions as a group that gets scheduled together. */
+
+ rtx set_dest = SET_DEST (curr_set);
+
+ if (GET_MODE (set_dest) != SImode)
+ return false;
+
+ /* We are trying to match:
+ prev (movw) == (set (reg r0) (const_int imm16))
+ curr (movt) == (set (zero_extract (reg r0)
+ (const_int 16)
+ (const_int 16))
+ (const_int imm16_1))
+ or
+ prev (movw) == (set (reg r1)
+ (high (symbol_ref ("SYM"))))
+ curr (movt) == (set (reg r0)
+ (lo_sum (reg r1)
+ (symbol_ref ("SYM")))) */
+
+ if (GET_CODE (set_dest) == ZERO_EXTRACT)
+ {
+ if (CONST_INT_P (SET_SRC (curr_set))
+ && CONST_INT_P (SET_SRC (prev_set))
+ && REG_P (XEXP (set_dest, 0))
+ && REG_P (SET_DEST (prev_set))
+ && REGNO (XEXP (set_dest, 0)) == REGNO (SET_DEST (prev_set)))
+ return true;
+
+ }
+ else if (GET_CODE (SET_SRC (curr_set)) == LO_SUM
+ && REG_P (SET_DEST (curr_set))
+ && REG_P (SET_DEST (prev_set))
+ && GET_CODE (SET_SRC (prev_set)) == HIGH
+ && REGNO (SET_DEST (curr_set)) == REGNO (SET_DEST (prev_set)))
+ return true;
+
+ return false;
+}
static bool
aarch_macro_fusion_pair_p (rtx_insn* prev, rtx_insn* curr)
{
- rtx set_dest;
rtx prev_set = single_set (prev);
rtx curr_set = single_set (curr);
@@ -29925,45 +29971,10 @@ aarch_macro_fusion_pair_p (rtx_insn* prev, rtx_insn* curr)
&& aarch_crypto_can_dual_issue (prev, curr))
return true;
- if (current_tune->fusible_ops & tune_params::FUSE_MOVW_MOVT)
- {
- /* We are trying to fuse
- movw imm / movt imm
- instructions as a group that gets scheduled together. */
-
- set_dest = SET_DEST (curr_set);
-
- if (GET_MODE (set_dest) != SImode)
- return false;
+ if (current_tune->fusible_ops & tune_params::FUSE_MOVW_MOVT
+ && arm_sets_movw_movt_fusible_p (prev_set, curr_set))
+ return true;
- /* We are trying to match:
- prev (movw) == (set (reg r0) (const_int imm16))
- curr (movt) == (set (zero_extract (reg r0)
- (const_int 16)
- (const_int 16))
- (const_int imm16_1))
- or
- prev (movw) == (set (reg r1)
- (high (symbol_ref ("SYM"))))
- curr (movt) == (set (reg r0)
- (lo_sum (reg r1)
- (symbol_ref ("SYM")))) */
- if (GET_CODE (set_dest) == ZERO_EXTRACT)
- {
- if (CONST_INT_P (SET_SRC (curr_set))
- && CONST_INT_P (SET_SRC (prev_set))
- && REG_P (XEXP (set_dest, 0))
- && REG_P (SET_DEST (prev_set))
- && REGNO (XEXP (set_dest, 0)) == REGNO (SET_DEST (prev_set)))
- return true;
- }
- else if (GET_CODE (SET_SRC (curr_set)) == LO_SUM
- && REG_P (SET_DEST (curr_set))
- && REG_P (SET_DEST (prev_set))
- && GET_CODE (SET_SRC (prev_set)) == HIGH
- && REGNO (SET_DEST (curr_set)) == REGNO (SET_DEST (prev_set)))
- return true;
- }
return false;
}
