The fix for PR83969 accidentally disallowed PRE_INC and PRE_DEC addresses
from being matched for the Y constraint leading to poor code generation.
The following patch resurrects the fix for PR84279 (early test for altivec
addresses) and then moves the call to rs6000_offsettable_memref_p below
the address_offset test, which is what allows PRE_INC/PRE_DEC addresses
to be matched.
Is this ok for trunk and the release branches where the earlier fixes
were backported to, assuming no bootstrap errors and the testsuite runs
do not show any regressions?
Peter
gcc/
PR target/85755
* config/rs6000/rs6000.c (mem_operand_gpr): Disable Altivec addresses.
Move call to rs6000_offsettable_memref_p below call to address_offset
to allow PRE_INC and PRE_DEC addresses.
gcc/testsuite/
PR target/85755
* gcc.target/powerpc/pr85755.c: New test.
Index: gcc/config/rs6000/rs6000.c
===================================================================
--- gcc/config/rs6000/rs6000.c (revision 261279)
+++ gcc/config/rs6000/rs6000.c (working copy)
@@ -7997,15 +7997,19 @@ mem_operand_gpr (rtx op, machine_mode mo
int extra;
rtx addr = XEXP (op, 0);
- /* Don't allow non-offsettable addresses. See PRs 83969 and 84279. */
- if (!rs6000_offsettable_memref_p (op, mode, false))
+ /* PR84279: Don't allow altivec addresses like (mem (and (plus ...))). */
+ if (GET_CODE (addr) == AND)
return false;
- op = address_offset (addr);
- if (op == NULL_RTX)
+ rtx offset_op = address_offset (addr);
+ if (offset_op == NULL_RTX)
return true;
- offset = INTVAL (op);
+ /* PR83969: Don't allow non-offsettable addresses. */
+ if (!rs6000_offsettable_memref_p (op, mode, false))
+ return false;
+
+ offset = INTVAL (offset_op);
if (TARGET_POWERPC64 && (offset & 3) != 0)
return false;
Index: gcc/testsuite/gcc.target/powerpc/pr85755.c
===================================================================
--- gcc/testsuite/gcc.target/powerpc/pr85755.c (nonexistent)
+++ gcc/testsuite/gcc.target/powerpc/pr85755.c (working copy)
@@ -0,0 +1,24 @@
+/* { dg-do compile { target { powerpc*-*-* } } } */
+/* { dg-skip-if "" { powerpc*-*-darwin* } } */
+/* { dg-require-effective-target powerpc_p8vector_ok } */
+/* { dg-skip-if "do not override -mcpu" { powerpc*-*-* } { "-mcpu=*" } {
"-mcpu=power8" } } */
+/* { dg-options "-O1 -mcpu=power8" } */
+
+void
+preinc (long *q, long n)
+{
+ long i;
+ for (i = 0; i < n; i++)
+ q[i] = i;
+}
+
+void
+predec (long *q, long n)
+{
+ long i;
+ for (i = n; i >= 0; i--)
+ q[i] = i;
+}
+
+/* { dg-final { scan-assembler-times {\mstdu\M} 2 } } */
+/* { dg-final { scan-assembler-not {\mstfdu\M} } } */
