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[PATCH, rs6000] Use $ instead of . for PC

From: Bill Schmidt <wschmidt at linux dot vnet dot ibm dot com>
To: GCC Patches <gcc-patches at gcc dot gnu dot org>
Cc: Segher Boessenkool <segher at kernel dot crashing dot org>, David Edelsohn <dje dot gcc at gmail dot com>
Date: Fri, 19 Jan 2018 14:58:07 -0600
Subject: [PATCH, rs6000] Use $ instead of . for PC
Authentication-results: sourceware.org; auth=none

Hi,

My recent patches to trunk and gcc-7-branch for avoiding speculation of
indirect branches has a flaw, pointed out by David.  Usage of "." to
represent the program counter is not portable across all POWER
assemblers, particularly not being accepted on AIX.  "$" is the 
universally accepted alternative.  So change the code and the test
cases to use $ instead of . for this purpose.

Regstrap is in progress on powerpc64-linux-gnu and powerpc64le-linux-gnu.
Assuming no issues are found, is this okay for trunk and backport to 7?

Thanks,
Bill


[gcc]

2018-01-19  Bill Schmidt  <wschmidt@linux.vnet.ibm.com>

	* config/rs6000/rs6000.md (*sibcall_nonlocal_sysv<mode>): Change
	assembly output from . to $.
	(*sibcall_value_nonlocal_sysv<mode>): Likewise.
	(indirect_jump<mode>_nospec): Likewise.
	(*tablejump<mode>_internal1_nospec): Likewise.

[gcc/testsuite]

2018-01-19  Bill Schmidt  <wschmidt@linux.vnet.ibm.com>

	* gcc.target/powerpc/safe-indirect-jump-2.c: Change expected
	assembly output from . to $.
	* gcc.target/powerpc/safe-indirect-jump-3.c: Likewise.
	* gcc.target/powerpc/safe-indirect-jump-8.c: Likewise.


Index: gcc/config/rs6000/rs6000.md
===================================================================
--- gcc/config/rs6000/rs6000.md	(revision 256894)
+++ gcc/config/rs6000/rs6000.md	(working copy)
@@ -10987,7 +10987,7 @@
 	return \"b%T0\";
       else
 	/* Can use CR0 since it is volatile across sibcalls.  */
-	return \"crset eq\;beq%T0-\;b .\";
+	return \"crset eq\;beq%T0-\;b $\";
     }
   else if (DEFAULT_ABI == ABI_V4 && flag_pic)
     {
@@ -11044,7 +11044,7 @@
 	return \"b%T1\";
       else
 	/* Can use CR0 since it is volatile across sibcalls.  */
-	return \"crset eq\;beq%T1-\;b .\";
+	return \"crset eq\;beq%T1-\;b $\";
     }
   else if (DEFAULT_ABI == ABI_V4 && flag_pic)
     {
@@ -12566,7 +12566,7 @@
   [(set (pc) (match_operand:P 0 "register_operand" "c,*l"))
    (clobber (match_operand:CC 1 "cc_reg_operand" "=y,y"))]
   "!rs6000_speculate_indirect_jumps"
-  "crset %E1\;beq%T0- %1\;b ."
+  "crset %E1\;beq%T0- %1\;b $"
   [(set_attr "type" "jmpreg")
    (set_attr "length" "12")])
 
@@ -12672,7 +12672,7 @@
    (use (label_ref (match_operand 1)))
    (clobber (match_operand:CC 2 "cc_reg_operand" "=y,y"))]
   "!rs6000_speculate_indirect_jumps"
-  "crset %E2\;beq%T0- %2\;b ."
+  "crset %E2\;beq%T0- %2\;b $"
   [(set_attr "type" "jmpreg")
    (set_attr "length" "12")])
 
Index: gcc/testsuite/gcc.target/powerpc/safe-indirect-jump-2.c
===================================================================
--- gcc/testsuite/gcc.target/powerpc/safe-indirect-jump-2.c	(revision 256894)
+++ gcc/testsuite/gcc.target/powerpc/safe-indirect-jump-2.c	(working copy)
@@ -30,4 +30,4 @@ int foo (int x)
 
 /* { dg-final { scan-assembler "crset 30" } } */
 /* { dg-final { scan-assembler "beqctr- 7" } } */
-/* { dg-final { scan-assembler "b ." } } */
+/* { dg-final { scan-assembler "b $" } } */
Index: gcc/testsuite/gcc.target/powerpc/safe-indirect-jump-3.c
===================================================================
--- gcc/testsuite/gcc.target/powerpc/safe-indirect-jump-3.c	(revision 256894)
+++ gcc/testsuite/gcc.target/powerpc/safe-indirect-jump-3.c	(working copy)
@@ -49,4 +49,4 @@ int foo (int x)
 
 /* { dg-final { scan-assembler "crset 30" } } */
 /* { dg-final { scan-assembler "beqctr- 7" } } */
-/* { dg-final { scan-assembler "b ." } } */
+/* { dg-final { scan-assembler "b $" } } */
Index: gcc/testsuite/gcc.target/powerpc/safe-indirect-jump-8.c
===================================================================
--- gcc/testsuite/gcc.target/powerpc/safe-indirect-jump-8.c	(revision 256894)
+++ gcc/testsuite/gcc.target/powerpc/safe-indirect-jump-8.c	(working copy)
@@ -12,4 +12,4 @@ int bar ()
 
 /* { dg-final { scan-assembler "crset eq" } } */
 /* { dg-final { scan-assembler "beqctr-" } } */
-/* { dg-final { scan-assembler "b ." } } */
+/* { dg-final { scan-assembler "b $" } } */
Index: gcc/config/rs6000/rs6000.md
===================================================================
--- gcc/config/rs6000/rs6000.md	(revision 256894)
+++ gcc/config/rs6000/rs6000.md	(working copy)
@@ -10987,7 +10987,7 @@
 	return \"b%T0\";
       else
 	/* Can use CR0 since it is volatile across sibcalls.  */
-	return \"crset eq\;beq%T0-\;b .\";
+	return \"crset eq\;beq%T0-\;b $\";
     }
   else if (DEFAULT_ABI == ABI_V4 && flag_pic)
     {
@@ -11044,7 +11044,7 @@
 	return \"b%T1\";
       else
 	/* Can use CR0 since it is volatile across sibcalls.  */
-	return \"crset eq\;beq%T1-\;b .\";
+	return \"crset eq\;beq%T1-\;b $\";
     }
   else if (DEFAULT_ABI == ABI_V4 && flag_pic)
     {
@@ -12566,7 +12566,7 @@
   [(set (pc) (match_operand:P 0 "register_operand" "c,*l"))
    (clobber (match_operand:CC 1 "cc_reg_operand" "=y,y"))]
   "!rs6000_speculate_indirect_jumps"
-  "crset %E1\;beq%T0- %1\;b ."
+  "crset %E1\;beq%T0- %1\;b $"
   [(set_attr "type" "jmpreg")
    (set_attr "length" "12")])
 
@@ -12672,7 +12672,7 @@
    (use (label_ref (match_operand 1)))
    (clobber (match_operand:CC 2 "cc_reg_operand" "=y,y"))]
   "!rs6000_speculate_indirect_jumps"
-  "crset %E2\;beq%T0- %2\;b ."
+  "crset %E2\;beq%T0- %2\;b $"
   [(set_attr "type" "jmpreg")
    (set_attr "length" "12")])
 
Index: gcc/testsuite/gcc.target/powerpc/safe-indirect-jump-2.c
===================================================================
--- gcc/testsuite/gcc.target/powerpc/safe-indirect-jump-2.c	(revision 256894)
+++ gcc/testsuite/gcc.target/powerpc/safe-indirect-jump-2.c	(working copy)
@@ -30,4 +30,4 @@ int foo (int x)
 
 /* { dg-final { scan-assembler "crset 30" } } */
 /* { dg-final { scan-assembler "beqctr- 7" } } */
-/* { dg-final { scan-assembler "b ." } } */
+/* { dg-final { scan-assembler "b $" } } */
Index: gcc/testsuite/gcc.target/powerpc/safe-indirect-jump-3.c
===================================================================
--- gcc/testsuite/gcc.target/powerpc/safe-indirect-jump-3.c	(revision 256894)
+++ gcc/testsuite/gcc.target/powerpc/safe-indirect-jump-3.c	(working copy)
@@ -49,4 +49,4 @@ int foo (int x)
 
 /* { dg-final { scan-assembler "crset 30" } } */
 /* { dg-final { scan-assembler "beqctr- 7" } } */
-/* { dg-final { scan-assembler "b ." } } */
+/* { dg-final { scan-assembler "b $" } } */
Index: gcc/testsuite/gcc.target/powerpc/safe-indirect-jump-8.c
===================================================================
--- gcc/testsuite/gcc.target/powerpc/safe-indirect-jump-8.c	(revision 256894)
+++ gcc/testsuite/gcc.target/powerpc/safe-indirect-jump-8.c	(working copy)
@@ -12,4 +12,4 @@ int bar ()
 
 /* { dg-final { scan-assembler "crset eq" } } */
 /* { dg-final { scan-assembler "beqctr-" } } */
-/* { dg-final { scan-assembler "b ." } } */
+/* { dg-final { scan-assembler "b $" } } */

Follow-Ups:
- Re: [PATCH, rs6000] Use $ instead of . for PC
  - From: Bill Schmidt
- Re: [PATCH, rs6000] Use $ instead of . for PC
  - From: Jakub Jelinek
- Re: [PATCH, rs6000] Use $ instead of . for PC
  - From: David Edelsohn

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