Hi,
It's been determined that we won't recommend use of the recently added
undocumented option -mno-speculate-indirect-jumps. This patch provides
a warning indicating that the option is deprecated. We will leave the
code in place for potential emergency use (not expected), and plan to
remove it completely in GCC 9.
Bootstrapped and tested on powerpc64le-linux-gnu with no regressions.
Is this okay for trunk? At least one distribution partner has also
requested that we backport this to the GCC 7 branch for 7.4. Is that
okay as well?
Thanks,
Bill
[gcc]
2018-02-05 Bill Schmidt <wschm...@linux.vnet.ibm.com>
* config/rs6000/rs6000.c (rs6000_option_override_internal):
Display warning message for -mno-speculate-indirect-jumps.
[gcc/testsuite]
2018-02-05 Bill Schmidt <wschm...@linux.vnet.ibm.com>
* gcc.target/powerpc/safe-indirect-jump-1.c: Detect deprecation
warning for -mno-speculate-indirect-jumps.
* gcc.target/powerpc/safe-indirect-jump-2.c: Likewise.
* gcc.target/powerpc/safe-indirect-jump-3.c: Likewise.
* gcc.target/powerpc/safe-indirect-jump-4.c: Likewise.
* gcc.target/powerpc/safe-indirect-jump-5.c: Likewise.
* gcc.target/powerpc/safe-indirect-jump-6.c: Likewise.
* gcc.target/powerpc/safe-indirect-jump-7.c: Likewise.
Index: gcc/config/rs6000/rs6000.c
===================================================================
--- gcc/config/rs6000/rs6000.c (revision 257367)
+++ gcc/config/rs6000/rs6000.c (working copy)
@@ -5295,6 +5295,11 @@ rs6000_option_override_internal (bool global_init_
if (TARGET_LINK_STACK == -1)
SET_TARGET_LINK_STACK (rs6000_tune == PROCESSOR_PPC476 && flag_pic);
+ /* Deprecate use of -mno-speculate-indirect-jumps. */
+ if (!rs6000_speculate_indirect_jumps)
+ warning (0, "%qs is deprecated and not recommended in any circumstances",
+ "-mno-speculate-indirect-jumps");
+
return ret;
}
Index: gcc/testsuite/gcc.target/powerpc/safe-indirect-jump-1.c
===================================================================
--- gcc/testsuite/gcc.target/powerpc/safe-indirect-jump-1.c (revision
257367)
+++ gcc/testsuite/gcc.target/powerpc/safe-indirect-jump-1.c (working copy)
@@ -1,5 +1,6 @@
/* { dg-do compile } */
/* { dg-additional-options "-mno-speculate-indirect-jumps" } */
+/* { dg-warning "'-mno-speculate-indirect-jumps' is deprecated" "" { target
*-*-* } 0 } */
/* Test for deliberate misprediction of indirect calls. */
Index: gcc/testsuite/gcc.target/powerpc/safe-indirect-jump-2.c
===================================================================
--- gcc/testsuite/gcc.target/powerpc/safe-indirect-jump-2.c (revision
257367)
+++ gcc/testsuite/gcc.target/powerpc/safe-indirect-jump-2.c (working copy)
@@ -1,5 +1,6 @@
/* { dg-do compile } */
/* { dg-options "-mno-speculate-indirect-jumps" } */
+/* { dg-warning "'-mno-speculate-indirect-jumps' is deprecated" "" { target
*-*-* } 0 } */
/* Test for deliberate misprediction of computed goto. */
Index: gcc/testsuite/gcc.target/powerpc/safe-indirect-jump-3.c
===================================================================
--- gcc/testsuite/gcc.target/powerpc/safe-indirect-jump-3.c (revision
257367)
+++ gcc/testsuite/gcc.target/powerpc/safe-indirect-jump-3.c (working copy)
@@ -1,5 +1,6 @@
/* { dg-do compile } */
/* { dg-options "-mno-speculate-indirect-jumps" } */
+/* { dg-warning "'-mno-speculate-indirect-jumps' is deprecated" "" { target
*-*-* } 0 } */
/* Test for deliberate misprediction of jump tables. */
Index: gcc/testsuite/gcc.target/powerpc/safe-indirect-jump-4.c
===================================================================
--- gcc/testsuite/gcc.target/powerpc/safe-indirect-jump-4.c (revision
257367)
+++ gcc/testsuite/gcc.target/powerpc/safe-indirect-jump-4.c (working copy)
@@ -1,5 +1,6 @@
/* { dg-do run } */
/* { dg-additional-options "-mno-speculate-indirect-jumps" } */
+/* { dg-warning "'-mno-speculate-indirect-jumps' is deprecated" "" { target
*-*-* } 0 } */
/* Test for deliberate misprediction of indirect calls for ELFv2. */
Index: gcc/testsuite/gcc.target/powerpc/safe-indirect-jump-5.c
===================================================================
--- gcc/testsuite/gcc.target/powerpc/safe-indirect-jump-5.c (revision
257367)
+++ gcc/testsuite/gcc.target/powerpc/safe-indirect-jump-5.c (working copy)
@@ -1,5 +1,6 @@
/* { dg-do run } */
/* { dg-additional-options "-mno-speculate-indirect-jumps -Wno-pedantic" } */
+/* { dg-warning "'-mno-speculate-indirect-jumps' is deprecated" "" { target
*-*-* } 0 } */
/* Test for deliberate misprediction of computed goto. */
Index: gcc/testsuite/gcc.target/powerpc/safe-indirect-jump-6.c
===================================================================
--- gcc/testsuite/gcc.target/powerpc/safe-indirect-jump-6.c (revision
257367)
+++ gcc/testsuite/gcc.target/powerpc/safe-indirect-jump-6.c (working copy)
@@ -1,5 +1,6 @@
/* { dg-do run } */
/* { dg-additional-options "-mno-speculate-indirect-jumps" } */
+/* { dg-warning "'-mno-speculate-indirect-jumps' is deprecated" "" { target
*-*-* } 0 } */
/* Test for deliberate misprediction of jump tables. */
Index: gcc/testsuite/gcc.target/powerpc/safe-indirect-jump-7.c
===================================================================
--- gcc/testsuite/gcc.target/powerpc/safe-indirect-jump-7.c (revision
257367)
+++ gcc/testsuite/gcc.target/powerpc/safe-indirect-jump-7.c (working copy)
@@ -1,5 +1,6 @@
/* { dg-do compile } */
/* { dg-additional-options "-mno-speculate-indirect-jumps" } */
+/* { dg-warning "'-mno-speculate-indirect-jumps' is deprecated" "" { target
*-*-* } 0 } */
/* Test for deliberate misprediction of indirect calls. */
