I will be starting to put out the patches to enable pc-relative support for a
future machine on the PowerPC.
Until those patches are approved and committed, we need to change the defaults
for the target so that pc-relative isn't default. Right now, we have the parts
of the compiler that does calls, etc. able to generate the appropriate
pc-relative calls, but the addressing modes still use the TOC calls.
Unfortunately, this means the TOC register is not properly set up in the
prologue.
I have tested these patches and the don't generate any test suite regressions.
I have visually inspected the code to make sure the calls are using the TOC abi
instead of the pc-relative. I did fix the few tests for pc-relative support to
add the necessary flags (-mpcrel) or GCC target pragma options (pcrel and
no-pcrel). In addition, I made the -mpcrel and -mprefixed-addr options behave
like other options (i.e. if you do -mpcrel, it also enables -mcpu=target and
-mprefixed-addr).
Can I check these patches into the trunk?
[gcc]
2019-06-06 Michael Meissner <meiss...@linux.ibm.com>
* config/rs6000/rs6000-cpus.def (ISA_FUTURE_MASKS_SERVER): Delete
enabling -mprefixed-addr and -mpcrel by default.
* config/rs6000/rs6000.c (rs6000_option_override_internal): Make
-mpcrel and -mprefixed-addr act like other swtiches (i.e. using
-mpcrel automatically sets -mcpu=future and -mprefixed-addr, and
-mprefixed-addr automatically sets just -mcpu=future). Clean up
some thinkos in reporting errors for -mpcrel and -mprefixed-addr.
[gcc/testsuite]
2019-06-06 Michael Meissner <meiss...@linux.ibm.com>
* gcc.target/powerpc/localentry-1.c: Add -mpcrel option.
* gcc.target/powerpc/localentry-detect-1.c: Explicitly set and
unset -mpcrel in the target pragmas.
* gcc.target/powerpc/notoc-direct-1.c: Add -mpcrel option.
* gcc.target/powerpc/pcrel-sibcall-1.c: Explicitly set and
unset -mpcrel in the target pragmas.
Index: gcc/config/rs6000/rs6000-cpus.def
===================================================================
--- gcc/config/rs6000/rs6000-cpus.def (revision 272004)
+++ gcc/config/rs6000/rs6000-cpus.def (working copy)
@@ -77,9 +77,7 @@
/* Support for a future processor's features. */
#define ISA_FUTURE_MASKS_SERVER (ISA_3_0_MASKS_SERVER
\
- | OPTION_MASK_FUTURE \
- | OPTION_MASK_PCREL \
- | OPTION_MASK_PREFIXED_ADDR)
+ | OPTION_MASK_FUTURE) \
/* Flags that need to be turned off if -mno-future. */
#define OTHER_FUTURE_MASKS (OPTION_MASK_PCREL \
Index: gcc/config/rs6000/rs6000.c
===================================================================
--- gcc/config/rs6000/rs6000.c (revision 272004)
+++ gcc/config/rs6000/rs6000.c (working copy)
@@ -3896,8 +3896,15 @@ rs6000_option_override_internal (bool gl
ignore_masks = rs6000_disable_incompatible_switches ();
/* For the newer switches (vsx, dfp, etc.) set some of the older options,
- unless the user explicitly used the -mno-<option> to disable the code. */
- if (TARGET_P9_VECTOR || TARGET_MODULO || TARGET_P9_MISC)
+ unless the user explicitly used the -mno-<option> to disable the code. At
+ present -mfuture does not enable prefixed address or pc-relative support,
+ so if those are specified, enable the necessary additional bits. */
+ if (TARGET_PCREL)
+ rs6000_isa_flags |= ((ISA_FUTURE_MASKS_SERVER
+ | OPTION_MASK_PREFIXED_ADDR) & ~ignore_masks);
+ else if (TARGET_PREFIXED_ADDR)
+ rs6000_isa_flags |= (ISA_FUTURE_MASKS_SERVER & ~ignore_masks);
+ else if (TARGET_P9_VECTOR || TARGET_MODULO || TARGET_P9_MISC)
rs6000_isa_flags |= (ISA_3_0_MASKS_SERVER & ~ignore_masks);
else if (TARGET_P9_MINMAX)
{
@@ -4248,7 +4255,7 @@ rs6000_option_override_internal (bool gl
/* -mpcrel requires prefixed load/store addressing. */
if (TARGET_PCREL && !TARGET_PREFIXED_ADDR)
{
- if ((rs6000_isa_flags_explicit & OPTION_MASK_PCREL) != 0)
+ if ((rs6000_isa_flags_explicit & OPTION_MASK_PREFIXED_ADDR) != 0)
error ("%qs requires %qs", "-mpcrel", "-mprefixed-addr");
rs6000_isa_flags &= ~OPTION_MASK_PCREL;
@@ -4257,7 +4264,7 @@ rs6000_option_override_internal (bool gl
/* -mprefixed-addr (and hence -mpcrel) requires -mcpu=future. */
if (TARGET_PREFIXED_ADDR && !TARGET_FUTURE)
{
- if ((rs6000_isa_flags_explicit & OPTION_MASK_PCREL) != 0)
+ if ((rs6000_isa_flags_explicit & OPTION_MASK_FUTURE) != 0)
error ("%qs requires %qs", "-mprefixed-addr", "-mcpu=future");
rs6000_isa_flags &= ~(OPTION_MASK_PCREL | OPTION_MASK_PREFIXED_ADDR);
Index: gcc/testsuite/gcc.target/powerpc/localentry-1.c
===================================================================
--- gcc/testsuite/gcc.target/powerpc/localentry-1.c (revision 272004)
+++ gcc/testsuite/gcc.target/powerpc/localentry-1.c (working copy)
@@ -1,10 +1,11 @@
/* { dg-do compile } */
-/* { dg-options "-mdejagnu-cpu=future -O2" } */
+/* { dg-options "-mdejagnu-cpu=future -O2 -mpcrel" } */
/* { dg-require-effective-target powerpc_elfv2 } */
/* { dg-require-effective-target powerpc_future_ok } */
-/* Ensure we generate ".localentry fn,1" for both leaf and non-leaf
- functions. */
+/* Ensure we generate ".localentry fn,1" for both leaf and non-leaf functions.
+ At present, -mcpu=future does not enable pc-relative mode, so make sure we
+ enable it to be able to check for .localentry. */
extern int y (int);
Index: gcc/testsuite/gcc.target/powerpc/localentry-detect-1.c
===================================================================
--- gcc/testsuite/gcc.target/powerpc/localentry-detect-1.c (revision
272004)
+++ gcc/testsuite/gcc.target/powerpc/localentry-detect-1.c (working copy)
@@ -3,10 +3,12 @@
/* { dg-require-effective-target powerpc_future_ok } */
/* { dg-options "-O2 -mdejagnu-cpu=future" } */
-
+/* At present, -mcpu=future does not enable pc-relative mode. Enable it here
+ explicitly until it is turned on by default. */
+#pragma GCC target ("cpu=future,pcrel")
int localentry1 () { return 5; }
-#pragma GCC target ("cpu=power9")
+#pragma GCC target ("cpu=power9,no-pcrel")
int localentry2 () { return 5; }
/* { dg-final { scan-assembler {\.localentry\tlocalentry1,1\M} } } */
Index: gcc/testsuite/gcc.target/powerpc/notoc-direct-1.c
===================================================================
--- gcc/testsuite/gcc.target/powerpc/notoc-direct-1.c (revision 272004)
+++ gcc/testsuite/gcc.target/powerpc/notoc-direct-1.c (working copy)
@@ -1,10 +1,11 @@
/* { dg-do compile } */
-/* { dg-options "-mdejagnu-cpu=future -O2" } */
+/* { dg-options "-mdejagnu-cpu=future -O2 -mpcrel" } */
/* { dg-require-effective-target powerpc_elfv2 } */
/* { dg-require-effective-target powerpc_future_ok } */
-/* Test that calls generated from PC-relative code are
- annotated with @notoc. */
+/* Test that calls generated from PC-relative code are annotated with @notoc.
+ At present, -mcpu=future does not enable pc-relative mode. Enable it here
+ explicitly until it is turned on by default. */
extern int yy0 (int);
extern void yy1 (int);
Index: gcc/testsuite/gcc.target/powerpc/pcrel-sibcall-1.c
===================================================================
--- gcc/testsuite/gcc.target/powerpc/pcrel-sibcall-1.c (revision 272004)
+++ gcc/testsuite/gcc.target/powerpc/pcrel-sibcall-1.c (working copy)
@@ -3,9 +3,12 @@
/* { dg-require-effective-target powerpc_elfv2 } */
/* { dg-require-effective-target powerpc_future_ok } */
-/* Test that potential sibcalls are not generated when the caller preserves
- the TOC and the callee doesn't, or vice versa. */
+/* Test that potential sibcalls are not generated when the caller preserves the
+ TOC and the callee doesn't, or vice versa. At present, -mcpu=future does
+ not enable pc-relative mode. Enable it here explicitly until it is turned
+ on by default. */
+#pragma GCC target ("cpu=future,pcrel")
int x (void) __attribute__((noinline));
int y (void) __attribute__((noinline));
int xx (void) __attribute__((noinline));
@@ -25,7 +28,7 @@ int sib_call (void)
return x ();
}
-#pragma GCC target ("cpu=power9")
+#pragma GCC target ("cpu=power9,no-pcrel")
int normal_call (void)
{
return y ();
@@ -36,7 +39,7 @@ int xx (void)
return 1;
}
-#pragma GCC target ("cpu=future")
+#pragma GCC target ("cpu=future,pcrel")
int notoc_call (void)
{
return xx ();
--
Michael Meissner, IBM
IBM, M/S 2506R, 550 King Street, Littleton, MA 01460-6245, USA
email: meiss...@linux.ibm.com, phone: +1 (978) 899-4797
