Hi,
Uli Weigand discovered that the gcc.target/powerpc/swaps-p8-21.c test
case fails when large and small code models are used, rather than the
default medium code model. This is because analyze_swaps is determining
whether the mask used for a vperm insn is loaded from the constant pool,
and there is an extra indirection for such loads when the large or small
code model is used. This patch changes analyze_swaps to handle the
extra indirection correctly. A new test case variant is added to check
for it.
Bootstrapped and tested on powerpc64le-unknown-linux-gnu with no
regressions. Ok for trunk?
Thanks,
Bill
[gcc]
2015-12-01 Bill Schmidt <wschm...@linux.vnet.ibm.com>
* config/rs6000/rs6000.c (const_load_sequence_p): Handle extra
indirection for large and small code models.
(adjust_vperm): Likewise.
[gcc/testsuite]
2015-12-01 Bill Schmidt <wschm...@linux.vnet.ibm.com>
* gcc.target/powerpc/swaps-p8-22.c: New.
Index: gcc/config/rs6000/rs6000.c
===================================================================
--- gcc/config/rs6000/rs6000.c (revision 231083)
+++ gcc/config/rs6000/rs6000.c (working copy)
@@ -36613,7 +36613,12 @@ const_load_sequence_p (swap_web_entry *insn_entry,
rtx base, offset;
if (GET_CODE (tocrel_body) != SET)
return false;
- if (!toc_relative_expr_p (SET_SRC (tocrel_body), false))
+ /* There is an extra level of indirection for small/large
+ code models. */
+ rtx tocrel_expr = SET_SRC (tocrel_body);
+ if (GET_CODE (tocrel_expr) == MEM)
+ tocrel_expr = XEXP (tocrel_expr, 0);
+ if (!toc_relative_expr_p (tocrel_expr, false))
return false;
split_const (XVECEXP (tocrel_base, 0, 0), &base, &offset);
if (GET_CODE (base) != SYMBOL_REF || !CONSTANT_POOL_ADDRESS_P (base))
@@ -37294,10 +37299,19 @@ adjust_vperm (rtx_insn *insn)
to set tocrel_base; otherwise it would be unnecessary as we've
already established it will return true. */
rtx base, offset;
- if (!toc_relative_expr_p (SET_SRC (PATTERN (tocrel_insn)), false))
+ rtx tocrel_expr = SET_SRC (PATTERN (tocrel_insn));
+ /* There is an extra level of indirection for small/large code models. */
+ if (GET_CODE (tocrel_expr) == MEM)
+ tocrel_expr = XEXP (tocrel_expr, 0);
+ if (!toc_relative_expr_p (tocrel_expr, false))
gcc_unreachable ();
split_const (XVECEXP (tocrel_base, 0, 0), &base, &offset);
rtx const_vector = get_pool_constant (base);
+ /* With the extra indirection, get_pool_constant will produce the
+ real constant from the reg_equal expression, so get the real
+ constant. */
+ if (GET_CODE (const_vector) == SYMBOL_REF)
+ const_vector = get_pool_constant (const_vector);
gcc_assert (GET_CODE (const_vector) == CONST_VECTOR);
/* Create an adjusted mask from the initial mask. */
Index: gcc/testsuite/gcc.target/powerpc/swaps-p8-22.c
===================================================================
--- gcc/testsuite/gcc.target/powerpc/swaps-p8-22.c (revision 0)
+++ gcc/testsuite/gcc.target/powerpc/swaps-p8-22.c (working copy)
@@ -0,0 +1,29 @@
+/* { dg-do compile { target { powerpc64le-*-* } } } */
+/* { dg-skip-if "do not override -mcpu" { powerpc*-*-* } { "-mcpu=*" } {
"-mcpu=power8" } }
+/* { dg-options "-O2 -mcpu=power8 -maltivec -mcmodel=large" } */
+
+/* The expansion for vector character multiply introduces a vperm operation.
+ This tests that changing the vperm mask allows us to remove all swaps
+ from the generated code. It is a duplicate of swaps-p8-21.c, except
+ that it applies the large code model, which requires an extra indirection
+ in the load of the constant mask. */
+
+#include <altivec.h>
+
+void abort ();
+
+vector unsigned char r;
+vector unsigned char v =
+ { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 };
+vector unsigned char i =
+ { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 };
+
+int main ()
+{
+ int j;
+ r = v * i;
+ return 0;
+}
+
+/* { dg-final { scan-assembler-times "vperm" 1 } } */
+/* { dg-final { scan-assembler-not "xxpermdi" } } */
