Hi,
This patch fills in a gap from the previous -mno-speculate-indirect-jumps
patch. That patch didn't provide support for indirect calls using ABI_AIX
as the default ABI. This fills in that missing support and changes the
one related powerpc64le-only test case to be compiled for all subtargets.
After some analysis, it doesn't appear possible for sibcalls to be
generated for ELFv1 or ELFv2 using a bctr, given the need for a local
call to avoid the required TOC restore afterwards. I haven't been able
to find a way to get a bctr generated even when one could theoretically
prove the bctr must go to a local function.
This has been bootstrapped and tested on powerpc64le-linux-gnu with no
regressions. Testing is still ongoing for powerpc64-linux-gnu. Provided
that testing completes with no surprises, is this okay for trunk (and
shortly for backport to 7)?
Thanks!
Bill
[gcc]
2018-01-16 Bill Schmidt <wschm...@linux.vnet.ibm.com>
* config/rs6000/rs6000.md (*call_indirect_aix<mode>): Disable for
-mno-speculate-indirect-jumps.
(*call_indirect_aix<mode>_nospec): New define_insn.
(*call_value_indirect_aix<mode>): Disable for
-mno-speculate-indirect-jumps.
(*call_value_indirect_aix<mode>_nospec): New define_insn.
[gcc/testsuite]
2018-01-16 Bill Schmidt <wschm...@linux.vnet.ibm.com>
* gcc.target/powerpc/safe-indirect-jump-1.c: Remove
powerpc64le-only restriction.
Index: gcc/config/rs6000/rs6000.md
===================================================================
--- gcc/config/rs6000/rs6000.md (revision 256753)
+++ gcc/config/rs6000/rs6000.md (working copy)
@@ -10669,11 +10669,22 @@
(use (match_operand:P 2 "memory_operand" "<ptrm>,<ptrm>"))
(set (reg:P TOC_REGNUM) (unspec:P [(match_operand:P 3 "const_int_operand"
"n,n")] UNSPEC_TOCSLOT))
(clobber (reg:P LR_REGNO))]
- "DEFAULT_ABI == ABI_AIX"
+ "DEFAULT_ABI == ABI_AIX && rs6000_speculate_indirect_jumps"
"<ptrload> 2,%2\;b%T0l\;<ptrload> 2,%3(1)"
[(set_attr "type" "jmpreg")
(set_attr "length" "12")])
+(define_insn "*call_indirect_aix<mode>_nospec"
+ [(call (mem:SI (match_operand:P 0 "register_operand" "c,*l"))
+ (match_operand 1 "" "g,g"))
+ (use (match_operand:P 2 "memory_operand" "<ptrm>,<ptrm>"))
+ (set (reg:P TOC_REGNUM) (unspec:P [(match_operand:P 3 "const_int_operand"
"n,n")] UNSPEC_TOCSLOT))
+ (clobber (reg:P LR_REGNO))]
+ "DEFAULT_ABI == ABI_AIX && !rs6000_speculate_indirect_jumps"
+ "crset eq\;<ptrload> 2,%2\;beq%T0l-\;<ptrload> 2,%3(1)"
+ [(set_attr "type" "jmpreg")
+ (set_attr "length" "16")])
+
(define_insn "*call_value_indirect_aix<mode>"
[(set (match_operand 0 "" "")
(call (mem:SI (match_operand:P 1 "register_operand" "c,*l"))
@@ -10681,11 +10692,23 @@
(use (match_operand:P 3 "memory_operand" "<ptrm>,<ptrm>"))
(set (reg:P TOC_REGNUM) (unspec:P [(match_operand:P 4 "const_int_operand"
"n,n")] UNSPEC_TOCSLOT))
(clobber (reg:P LR_REGNO))]
- "DEFAULT_ABI == ABI_AIX"
+ "DEFAULT_ABI == ABI_AIX && rs6000_speculate_indirect_jumps"
"<ptrload> 2,%3\;b%T1l\;<ptrload> 2,%4(1)"
[(set_attr "type" "jmpreg")
(set_attr "length" "12")])
+(define_insn "*call_value_indirect_aix<mode>_nospec"
+ [(set (match_operand 0 "" "")
+ (call (mem:SI (match_operand:P 1 "register_operand" "c,*l"))
+ (match_operand 2 "" "g,g")))
+ (use (match_operand:P 3 "memory_operand" "<ptrm>,<ptrm>"))
+ (set (reg:P TOC_REGNUM) (unspec:P [(match_operand:P 4 "const_int_operand"
"n,n")] UNSPEC_TOCSLOT))
+ (clobber (reg:P LR_REGNO))]
+ "DEFAULT_ABI == ABI_AIX && !rs6000_speculate_indirect_jumps"
+ "crset eq\;<ptrload> 2,%3\;beq%T1l-\;<ptrload> 2,%4(1)"
+ [(set_attr "type" "jmpreg")
+ (set_attr "length" "16")])
+
;; Call to indirect functions with the ELFv2 ABI.
;; Operand0 is the addresss of the function to call
;; Operand2 is the offset of the stack location holding the current TOC pointer
Index: gcc/testsuite/gcc.target/powerpc/safe-indirect-jump-1.c
===================================================================
--- gcc/testsuite/gcc.target/powerpc/safe-indirect-jump-1.c (revision
256753)
+++ gcc/testsuite/gcc.target/powerpc/safe-indirect-jump-1.c (working copy)
@@ -1,4 +1,4 @@
-/* { dg-do compile { target { powerpc64le-*-* } } } */
+/* { dg-do compile } */
/* { dg-additional-options "-mno-speculate-indirect-jumps" } */
/* Test for deliberate misprediction of indirect calls for ELFv2. */
