[PATCH V3] report message for operator %a on unaddressible operand

[Jiufu Guo]

Hi,

For PR96866, when printing asm code for modifier "%a", an addressable
operand is required.  While the constraint "X" allow any kind of
operand even which is hard to get the address directly. e.g. extern
symbol whose address is in TOC.
An error message would be reported to indicate the invalid asm operand.

Compare with previous version, code comments and message are updated.

Bootstrap&regtest pass on ppc64{,le}.
Is this ok for trunk?

BR,
Jeff(Jiufu Guo)

        PR target/96866

gcc/ChangeLog:

        * config/rs6000/rs6000.cc (print_operand_address):

gcc/testsuite/ChangeLog:

        * gcc.target/powerpc/pr96866-1.c: New test.
        * gcc.target/powerpc/pr96866-2.c: New test.

---
 gcc/config/rs6000/rs6000.cc                  |  7 ++++++-
 gcc/testsuite/gcc.target/powerpc/pr96866-1.c | 18 ++++++++++++++++++
 gcc/testsuite/gcc.target/powerpc/pr96866-2.c | 13 +++++++++++++
 3 files changed, 37 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/gcc.target/powerpc/pr96866-1.c
 create mode 100644 gcc/testsuite/gcc.target/powerpc/pr96866-2.c

diff --git a/gcc/config/rs6000/rs6000.cc b/gcc/config/rs6000/rs6000.cc
index 117999613d8..7e7c36a1bad 100644
--- a/gcc/config/rs6000/rs6000.cc
+++ b/gcc/config/rs6000/rs6000.cc
@@ -14664,7 +14664,12 @@ print_operand_address (FILE *file, rtx x)
        fprintf (file, "@%s(%s)", SMALL_DATA_RELOC,
                 reg_names[SMALL_DATA_REG]);
       else
-       gcc_assert (!TARGET_TOC);
+       {
+         /* Do not support getting address directly from TOC, emit error.
+            No more work is needed for !TARGET_TOC. */
+         if (TARGET_TOC)
+           output_operand_lossage ("%%a requires an address of memory");
+       }
     }
   else if (GET_CODE (x) == PLUS && REG_P (XEXP (x, 0))
           && REG_P (XEXP (x, 1)))
diff --git a/gcc/testsuite/gcc.target/powerpc/pr96866-1.c 
b/gcc/testsuite/gcc.target/powerpc/pr96866-1.c
new file mode 100644
index 00000000000..bcebbd6e310
--- /dev/null
+++ b/gcc/testsuite/gcc.target/powerpc/pr96866-1.c
@@ -0,0 +1,18 @@
+/* The "%a" modifier can't get the address of extern symbol directly from TOC
+   with -fPIC, even the symbol is propgated for "X" constraint under -O2. */
+/* { dg-options "-fPIC -O2" } */
+
+/* It's to verify no ICE here, ignore error messages about invalid 'asm'.  */
+/* { dg-excess-errors "pr96866-1.c" } */
+
+int x[2];
+
+int __attribute__ ((noipa))
+f1 (void)
+{
+  int n;
+  int *p = x;
+  *p++;
+  __asm__ volatile("ld %0, %a1" : "=r"(n) : "X"(p));
+  return n;
+}
diff --git a/gcc/testsuite/gcc.target/powerpc/pr96866-2.c 
b/gcc/testsuite/gcc.target/powerpc/pr96866-2.c
new file mode 100644
index 00000000000..0577fd6d588
--- /dev/null
+++ b/gcc/testsuite/gcc.target/powerpc/pr96866-2.c
@@ -0,0 +1,13 @@
+/* The "%a" modifier can't get the address of extern symbol directly from TOC
+   with -fPIC. */
+/* { dg-options "-fPIC -O2" } */
+
+/* It's to verify no ICE here, ignore error messages about invalid 'asm'.  */
+/* { dg-excess-errors "pr96866-2.c" } */
+
+void
+f (void)
+{
+  extern int x;
+  __asm__ volatile("#%a0" ::"X"(&x));
+}
-- 
2.25.1