@@ -30,7 +30,6 @@ extern void rx_expand_prologue (void);
extern int rx_initial_elimination_offset (int, int);
#ifdef RTX_CODE
-extern bool rx_compare_redundant (rtx);
extern void rx_emit_stack_popm (rtx *, bool);
extern void rx_emit_stack_pushm (rtx *);
extern void rx_expand_epilogue (bool);
@@ -2602,155 +2602,6 @@ flags_from_mode (enum machine_mode mode)
}
}
-/* Returns true if a compare insn is redundant because it
- would only set flags that are already set correctly. */
-
-bool
-rx_compare_redundant (rtx cmp)
-{
- unsigned int flags_needed;
- unsigned int flags_set;
- rtx next;
- rtx prev;
- rtx source;
- rtx dest;
- static rtx cc_reg = NULL_RTX;
-
- if (cc_reg == NULL_RTX)
- cc_reg = gen_rtx_REG (CCmode, CC_REGNUM);
-
- /* We can only eliminate compares against 0. */
- if (GET_CODE (XEXP (SET_SRC (PATTERN (cmp)), 1)) != CONST_INT
- || INTVAL (XEXP (SET_SRC (PATTERN (cmp)), 1)) != 0)
- return false;
-
- /* Locate the branch insn that follows the
- compare and which tests the bits in the PSW. */
- next = cmp;
- do
- {
- /* If we have found an insn that sets or clobbers the CC
- register and it was not the IF_THEN_ELSE insn that we
- are looking for, then the comparison is redundant. */
- if (next != cmp && reg_mentioned_p (cc_reg, PATTERN (next)))
- return true;
-
- next = next_nonnote_insn (next);
-
- /* If we run out of insns without finding the
- user then the comparison is unnecessary. */
- if (next == NULL_RTX)
- return true;
-
- /* If we have found another comparison
- insn then the first one is redundant. */
- if (INSN_P (next)
- && GET_CODE (PATTERN (next)) == SET
- && REG_P (SET_DEST (PATTERN (next)))
- && REGNO (SET_DEST (PATTERN (next))) == CC_REGNUM)
- return true;
-
- /* If we have found another arithmetic/logic insn that
- sets the PSW flags then the comparison is redundant. */
- if (INSN_P (next)
- && GET_CODE (PATTERN (next)) == PARALLEL
- && GET_CODE (XVECEXP (PATTERN (next), 0, 1)) == SET
- && REG_P (SET_DEST (XVECEXP (PATTERN (next), 0, 1)))
- && REGNO (SET_DEST (XVECEXP (PATTERN (next), 0, 1))) == CC_REGNUM)
- return true;
-
- /* If we have found an unconditional branch then the
- PSW flags might be carried along with the jump, so
- the comparison is necessary. */
- if (INSN_P (next) && JUMP_P (next))
- {
- if (GET_CODE (PATTERN (next)) != SET)
- /* If the jump does not involve setting the PC
- then it is a return of some kind, and we know
- that the comparison is not used. */
- return true;
-
- if (GET_CODE (SET_SRC (PATTERN (next))) != IF_THEN_ELSE)
- return false;
- }
- }
- while (! INSN_P (next)
- || DEBUG_INSN_P (next)
- || GET_CODE (PATTERN (next)) != SET
- || GET_CODE (SET_SRC (PATTERN (next))) != IF_THEN_ELSE);
-
- flags_needed = flags_needed_for_conditional (XEXP (SET_SRC (PATTERN (next)), 0));
-
- /* Now look to see if there was a previous
- instruction which set the PSW bits. */
- source = XEXP (SET_SRC (PATTERN (cmp)), 0);
- prev = cmp;
- do
- {
- /* If this insn uses/sets/clobbers the CC register
- and it is not the insn that we are looking for
- below, then we must need the comparison. */
- if (prev != cmp && reg_mentioned_p (cc_reg, PATTERN (prev)))
- return false;
-
- prev = prev_nonnote_insn (prev);
-
- if (prev == NULL_RTX)
- return false;
-
- /* If we encounter an insn which changes the contents of
- the register which is the source of the comparison then
- we will definitely need the comparison. */
- if (INSN_P (prev)
- && GET_CODE (PATTERN (prev)) == SET
- && rtx_equal_p (SET_DEST (PATTERN (prev)), source))
- {
- /* Unless this instruction is a simple register move
- instruction. In which case we can continue our
- scan backwards, but now using the *source* of this
- set instruction. */
- if (REG_P (SET_SRC (PATTERN (prev))))
- source = SET_SRC (PATTERN (prev));
- /* We can also survive a sign-extension if the test is
- for EQ/NE. Note the same does not apply to zero-
- extension as this can turn a non-zero bit-pattern
- into zero. */
- else if (flags_needed == CC_FLAG_Z
- && GET_CODE (SET_SRC (PATTERN (prev))) == SIGN_EXTEND)
- source = XEXP (SET_SRC (PATTERN (prev)), 0);
- else
- return false;
- }
-
- /* A label means a possible branch into the
- code here, so we have to stop scanning. */
- if (LABEL_P (prev))
- return false;
- }
- while (! INSN_P (prev)
- || DEBUG_INSN_P (prev)
- || GET_CODE (PATTERN (prev)) != PARALLEL
- || GET_CODE (XVECEXP (PATTERN (prev), 0, 1)) != SET
- || ! REG_P (SET_DEST (XVECEXP (PATTERN (prev), 0, 1)))
- || REGNO (SET_DEST (XVECEXP (PATTERN (prev), 0, 1))) != CC_REGNUM);
-
- flags_set = flags_from_mode (GET_MODE (SET_DEST (XVECEXP (PATTERN (prev), 0, 1))));
-
- dest = SET_DEST (XVECEXP (PATTERN (prev), 0, 0));
- /* The destination of the previous arithmetic/logic instruction
- must match the source in the comparison operation. For registers
- we ignore the mode as there may have been a sign-extension involved. */
- if (! rtx_equal_p (source, dest))
- {
- if (REG_P (source) && REG_P (dest) && REGNO (dest) == REGNO (source))
- ;
- else
- return false;
- }
-
- return ((flags_set & flags_needed) == flags_needed);
-}
-
static int
rx_memory_move_cost (enum machine_mode mode, reg_class_t regclass, bool in)
{
@@ -340,12 +340,7 @@
(compare:CC (match_operand:SI 0 "register_operand" "r,r,r,r,r,r,r")
(match_operand:SI 1 "rx_source_operand" "r,Uint04,Int08,Sint16,Sint24,i,Q")))]
""
- {
- rx_float_compare_mode = false;
- if (rx_compare_redundant (insn))
- return "; Compare Eliminated: cmp %Q1, %0";
- return "cmp\t%Q1, %0";
- }
+ "cmp\t%Q1, %0"
[(set_attr "timings" "11,11,11,11,11,11,33")
(set_attr "length" "2,2,3,4,5,6,5")]
)
From: Richard Henderson <rth@twiddle.net> To be replaced by the generic compare_elim pass, but we need to disable this before fiddling with the arrangement of the arithmetic instructions, as required by the generic pass. --- gcc/config/rx/rx-protos.h | 1 - gcc/config/rx/rx.c | 149 --------------------------------------------- gcc/config/rx/rx.md | 7 +-- 3 files changed, 1 insertions(+), 156 deletions(-)