Hi
The patch optimized expansion for long long or double vec_reve builtin.
Bootstrapped and tested on powerpc64le-linux with no regressions.
Is this okay for trunk? Any recommendations? Thanks a lot.
ChangeLog
2021-09-06 Haochen Gui <guih...@linux.ibm.com>
gcc/
* config/rs6000/altivec.md (altivec_vreve<mode>2):
Modify the expansion when number of elements is 2.
gcc/testsuite/
* gcc.target/powerpc/vec_reve.c: New test.
patch.diff
diff --git a/gcc/config/rs6000/altivec.md b/gcc/config/rs6000/altivec.md
index 1351dafbc41..96e71979fbd 100644
--- a/gcc/config/rs6000/altivec.md
+++ b/gcc/config/rs6000/altivec.md
@@ -4063,6 +4063,13 @@ (define_expand "altivec_vreve<mode>2"
size = GET_MODE_UNIT_SIZE (<MODE>mode);
num_elements = GET_MODE_NUNITS (<MODE>mode);
+ if (num_elements == 2)
+ {
+ emit_insn (gen_vsx_xxpermdi_<mode> (operands[0], operands[1],
+ operands[1], GEN_INT (2)));
+ DONE;
+ }
+
for (j = 0; j < num_elements; j++)
for (i = 0; i < size; i++)
RTVEC_ELT (v, i + j * size)
diff --git a/gcc/testsuite/gcc.target/powerpc/vec_reve.c
b/gcc/testsuite/gcc.target/powerpc/vec_reve.c
new file mode 100644
index 00000000000..d86ce11ba91
--- /dev/null
+++ b/gcc/testsuite/gcc.target/powerpc/vec_reve.c
@@ -0,0 +1,17 @@
+/* { dg-do compile { target { powerpc*-*-* } } } */
+/* { dg-require-effective-target powerpc_altivec_ok } */
+/* { dg-options "-O2 -maltivec" } */
+
+#include <altivec.h>
+
+vector double foo1 (vector double a)
+{
+ return vec_reve (a);
+}
+
+vector long long foo2 (vector long long a)
+{
+ return vec_reve (a);
+}
+
+/* { dg-final { scan-assembler-times {\mxxpermdi\M} 2 } } */
