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-rw-r--r--gcc/config/s390/s390.c187
1 files changed, 131 insertions, 56 deletions
diff --git a/gcc/config/s390/s390.c b/gcc/config/s390/s390.c
index 7ad230ea3a9..eb08828c29b 100644
--- a/gcc/config/s390/s390.c
+++ b/gcc/config/s390/s390.c
@@ -9589,21 +9589,6 @@ s390_optimize_prologue (void)
}
}
-
-/* Exchange the two operands of COND, and swap its mask so that the
- semantics does not change. */
-static void
-s390_swap_cmp (rtx cond)
-{
- enum rtx_code code = swap_condition (GET_CODE (cond));
- rtx tmp = XEXP (cond, 0);
-
- XEXP (cond, 0) = XEXP (cond, 1);
- XEXP (cond, 1) = tmp;
- PUT_CODE (cond, code);
-}
-
-
/* Returns 1 if INSN reads the value of REG for purposes not related
to addressing of memory, and 0 otherwise. */
static int
@@ -9613,6 +9598,71 @@ s390_non_addr_reg_read_p (rtx reg, rtx insn)
&& !reg_used_in_mem_p (REGNO (reg), PATTERN (insn));
}
+/* Starting from INSN find_cond_jump looks downwards in the insn
+ stream for a single jump insn which is the last user of the
+ condition code set in INSN. */
+static rtx
+find_cond_jump (rtx insn)
+{
+ for (; insn; insn = NEXT_INSN (insn))
+ {
+ rtx ite, cc;
+
+ if (LABEL_P (insn))
+ break;
+
+ if (!JUMP_P (insn))
+ {
+ if (reg_mentioned_p (gen_rtx_REG (CCmode, CC_REGNUM), insn))
+ break;
+ continue;
+ }
+
+ /* This will be triggered by a return. */
+ if (GET_CODE (PATTERN (insn)) != SET)
+ break;
+
+ gcc_assert (SET_DEST (PATTERN (insn)) == pc_rtx);
+ ite = SET_SRC (PATTERN (insn));
+
+ if (GET_CODE (ite) != IF_THEN_ELSE)
+ break;
+
+ cc = XEXP (XEXP (ite, 0), 0);
+ if (!REG_P (cc) || !CC_REGNO_P (REGNO (cc)))
+ break;
+
+ if (find_reg_note (insn, REG_DEAD, cc))
+ return insn;
+ break;
+ }
+
+ return NULL_RTX;
+}
+
+/* Swap the condition in COND and the operands in OP0 and OP1 so that
+ the semantics does not change. If NULL_RTX is passed as COND the
+ function tries to find the conditional jump starting with INSN. */
+static void
+s390_swap_cmp (rtx cond, rtx *op0, rtx *op1, rtx insn)
+{
+ rtx tmp = *op0;
+
+ if (cond == NULL_RTX)
+ {
+ rtx jump = find_cond_jump (NEXT_INSN (insn));
+ jump = jump ? single_set (jump) : NULL_RTX;
+
+ if (jump == NULL_RTX)
+ return;
+
+ cond = XEXP (XEXP (jump, 1), 0);
+ }
+
+ *op0 = *op1;
+ *op1 = tmp;
+ PUT_CODE (cond, swap_condition (GET_CODE (cond)));
+}
/* On z10, instructions of the compare-and-branch family have the
property to access the register occurring as second operand with
@@ -9622,7 +9672,7 @@ s390_non_addr_reg_read_p (rtx reg, rtx insn)
pipeline recycles, thereby causing significant performance decline.
This function locates such situations and exchanges the two
operands of the compare. */
-static void
+static void
s390_z10_optimize_cmp (void)
{
rtx insn, prev_insn, next_insn;
@@ -9630,54 +9680,79 @@ s390_z10_optimize_cmp (void)
for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
{
+ rtx cond, *op0, *op1;
+
if (!INSN_P (insn) || INSN_CODE (insn) <= 0)
continue;
- if (get_attr_z10prop (insn) == Z10PROP_Z10_COBRA)
+ if (GET_CODE (PATTERN (insn)) == PARALLEL)
{
- rtx op0, op1, pattern, jump_expr, cond;
+ /* Handle compare and branch and branch on count
+ instructions. */
+ rtx pattern = single_set (insn);
- /* Extract the comparison´s condition and its operands. */
- pattern = single_set (insn);
- gcc_assert (GET_CODE (pattern) == SET);
- jump_expr = XEXP (pattern, 1);
- gcc_assert (GET_CODE (jump_expr) == IF_THEN_ELSE);
- cond = XEXP (jump_expr, 0);
- op0 = XEXP (cond, 0);
- op1 = XEXP (cond, 1);
+ if (!pattern
+ || SET_DEST (pattern) != pc_rtx
+ || GET_CODE (SET_SRC (pattern)) != IF_THEN_ELSE)
+ continue;
- /* Swap the COMPARE´s arguments and its mask if there is a
- conflicting access in the previous insn. */
- prev_insn = PREV_INSN (insn);
- if (prev_insn != NULL_RTX && INSN_P (prev_insn)
- && reg_referenced_p (op1, PATTERN (prev_insn)))
- {
- s390_swap_cmp (cond);
- op0 = XEXP (cond, 0);
- op1 = XEXP (cond, 1);
- }
+ cond = XEXP (SET_SRC (pattern), 0);
+ op0 = &XEXP (cond, 0);
+ op1 = &XEXP (cond, 1);
+ }
+ else if (GET_CODE (PATTERN (insn)) == SET)
+ {
+ rtx src, dest;
- /* Check if there is a conflict with the next insn. If there
- was no conflict with the previous insn, then swap the
- COMPARE´s arguments and its mask. If we already swapped
- the operands, or if swapping them would cause a conflict
- with the previous insn, issue a NOP after the COMPARE in
- order to separate the two instuctions. */
- next_insn = NEXT_INSN (insn);
- if (next_insn != NULL_RTX && INSN_P (next_insn)
- && s390_non_addr_reg_read_p (op1, next_insn))
- {
- if (s390_non_addr_reg_read_p (op0, prev_insn))
- {
- if (REGNO(op1) == 0)
- emit_insn_after (gen_nop1 (), insn);
- else
- emit_insn_after (gen_nop (), insn);
- added_NOPs = 1;
- }
+ /* Handle normal compare instructions. */
+ src = SET_SRC (PATTERN (insn));
+ dest = SET_DEST (PATTERN (insn));
+
+ if (!REG_P (dest)
+ || !CC_REGNO_P (REGNO (dest))
+ || GET_CODE (src) != COMPARE)
+ continue;
+
+ /* s390_swap_cmp will try to find the conditional
+ jump when passing NULL_RTX as condition. */
+ cond = NULL_RTX;
+ op0 = &XEXP (src, 0);
+ op1 = &XEXP (src, 1);
+ }
+ else
+ continue;
+
+ if (!REG_P (*op0) || !REG_P (*op1))
+ continue;
+
+ /* Swap the COMPARE arguments and its mask if there is a
+ conflicting access in the previous insn. */
+ prev_insn = PREV_INSN (insn);
+ if (prev_insn != NULL_RTX && INSN_P (prev_insn)
+ && reg_referenced_p (*op1, PATTERN (prev_insn)))
+ s390_swap_cmp (cond, op0, op1, insn);
+
+ /* Check if there is a conflict with the next insn. If there
+ was no conflict with the previous insn, then swap the
+ COMPARE arguments and its mask. If we already swapped
+ the operands, or if swapping them would cause a conflict
+ with the previous insn, issue a NOP after the COMPARE in
+ order to separate the two instuctions. */
+ next_insn = NEXT_INSN (insn);
+ if (next_insn != NULL_RTX && INSN_P (next_insn)
+ && s390_non_addr_reg_read_p (*op1, next_insn))
+ {
+ if (prev_insn != NULL_RTX && INSN_P (prev_insn)
+ && s390_non_addr_reg_read_p (*op0, prev_insn))
+ {
+ if (REGNO (*op1) == 0)
+ emit_insn_after (gen_nop1 (), insn);
else
- s390_swap_cmp (cond);
+ emit_insn_after (gen_nop (), insn);
+ added_NOPs = 1;
}
+ else
+ s390_swap_cmp (cond, op0, op1, insn);
}
}
@@ -9799,7 +9874,7 @@ s390_reorg (void)
/* Eliminate z10-specific pipeline recycles related to some compare
instructions. */
- if (TARGET_Z10)
+ if (s390_tune == PROCESSOR_2097_Z10)
s390_z10_optimize_cmp ();
}
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