If there is no cost information from the backend, the middle end
estimates the cost of if_then_else, which has three operands, as
3 instructions (i.e. 12 units). Define its cost as a single machine
cycle, ignoring the cost of actually taking the branch, to enable
more if-conversion optimizations.
gcc/ChangeLog:
* config/loongarch/loongarch.cc (loongarch_rtx_costs):
<IF_THEN_ELSE>: New case.
gcc/testsuite/ChangeLog:
* gcc.target/loongarch/ifcvt-1.c: New test.
---
gcc/config/loongarch/loongarch.cc | 4 ++++
gcc/testsuite/gcc.target/loongarch/ifcvt-1.c | 22 ++++++++++++++++++++
2 files changed, 26 insertions(+)
create mode 100644 gcc/testsuite/gcc.target/loongarch/ifcvt-1.c
diff --git a/gcc/config/loongarch/loongarch.cc
b/gcc/config/loongarch/loongarch.cc
index 1715b483c96..413de2e3906 100644
--- a/gcc/config/loongarch/loongarch.cc
+++ b/gcc/config/loongarch/loongarch.cc
@@ -4082,6 +4082,10 @@ loongarch_rtx_costs (rtx x, machine_mode mode, int
outer_code,
switch (code)
{
+ case IF_THEN_ELSE:
+ *total = COSTS_N_INSNS (1);
+ return true;
+
case CONST_INT:
if (TARGET_64BIT && outer_code == AND && UINTVAL (x) == 0xffffffff)
{
diff --git a/gcc/testsuite/gcc.target/loongarch/ifcvt-1.c
b/gcc/testsuite/gcc.target/loongarch/ifcvt-1.c
new file mode 100644
index 00000000000..64a151a92f4
--- /dev/null
+++ b/gcc/testsuite/gcc.target/loongarch/ifcvt-1.c
@@ -0,0 +1,22 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+/* { dg-final { scan-assembler-times "maskeqz" 2 } } */
+/* { dg-final { scan-assembler-times "masknez" 2 } } */
+
+int
+remove_one_fast (int *move_ordering, const int num_moves, int mark)
+{
+ int i, best = -1000000;
+ int tmp = 0;
+
+ for (i = mark; i < num_moves; i++)
+ {
+ if (move_ordering[i] > best)
+ {
+ best = move_ordering[i];
+ tmp = i;
+ }
+ }
+
+ return tmp;
+}
--
2.20.1
