[gcc(refs/users/marxin/heads/marxin-gcc-benchmark-branch)] powerpc: Fix -fstack-clash-protection -mprefixed-addr ICE [PR93122]

[Martin Liska]

https://gcc.gnu.org/g:c006911de91ca9e23d7d2df069499c768d215eac

commit c006911de91ca9e23d7d2df069499c768d215eac
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Fri Feb 7 11:09:03 2020 +0100

    powerpc: Fix -fstack-clash-protection -mprefixed-addr ICE [PR93122]
    
    As mentioned in the PR, the following testcase ICEs because rs, while valid
    add_operand is not valid add_cint_operand and so gen_add3_insn fails,
    because it doesn't meet the expander predicates.
    
    Here is what I meant as the alternative, i.e. don't check any predicates,
    just gen_add3_insn, if that fails, force rs into register and retry.
    And, add REG_FRAME_RELATED_EXPR note always when we haven't emitted a single
    insn that has rtl exactly matching what we'd add the REG_FRAME_RELATED_EXPR
    with (in that case, dwarf2cfi.c is able to figure it out by itself, no need
    to waste compile time memory).
    
    2020-02-07  Jakub Jelinek  <jakub@redhat.com>
    
            PR target/93122
            * config/rs6000/rs6000-logue.c
            (rs6000_emit_probe_stack_range_stack_clash): Always use gen_add3_insn,
            if it fails, move rs into end_addr and retry.  Add
            REG_FRAME_RELATED_EXPR note whenever it returns more than one insn or
            the insn pattern doesn't describe well what exactly happens to
            dwarf2cfi.c.
    
            * gcc.target/powerpc/pr93122.c: New test.

Diff:
---
 gcc/ChangeLog                              |  8 +++++++
 gcc/config/rs6000/rs6000-logue.c           | 36 +++++++++++++++++++++---------
 gcc/testsuite/ChangeLog                    |  5 +++++
 gcc/testsuite/gcc.target/powerpc/pr93122.c | 12 ++++++++++
 4 files changed, 50 insertions(+), 11 deletions(-)

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index e56eaba7327..a7babd25be4 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,13 @@
 2020-02-07  Jakub Jelinek  <jakub@redhat.com>
 
+	PR target/93122
+	* config/rs6000/rs6000-logue.c
+	(rs6000_emit_probe_stack_range_stack_clash): Always use gen_add3_insn,
+	if it fails, move rs into end_addr and retry.  Add
+	REG_FRAME_RELATED_EXPR note whenever it returns more than one insn or
+	the insn pattern doesn't describe well what exactly happens to
+	dwarf2cfi.c.
+
 	PR target/93594
 	* config/i386/predicates.md (avx_identity_operand): Remove.
 	* config/i386/sse.md (*avx_vec_concat<mode>_1): Remove.
diff --git a/gcc/config/rs6000/rs6000-logue.c b/gcc/config/rs6000/rs6000-logue.c
index 0db53d8375a..fecc3e6f780 100644
--- a/gcc/config/rs6000/rs6000-logue.c
+++ b/gcc/config/rs6000/rs6000-logue.c
@@ -1604,20 +1604,34 @@ rs6000_emit_probe_stack_range_stack_clash (HOST_WIDE_INT orig_size,
       rtx end_addr
 	= copy_reg ? gen_rtx_REG (Pmode, 0) : gen_rtx_REG (Pmode, 12);
       rtx rs = GEN_INT (-rounded_size);
-      rtx_insn *insn;
-      if (add_operand (rs, Pmode))
-	insn = emit_insn (gen_add3_insn (end_addr, stack_pointer_rtx, rs));
+      rtx_insn *insn = gen_add3_insn (end_addr, stack_pointer_rtx, rs);
+      if (insn == NULL)
+	{
+	  emit_move_insn (end_addr, rs);
+	  insn = gen_add3_insn (end_addr, end_addr, stack_pointer_rtx);
+	  gcc_assert (insn);
+	}
+      bool add_note = false;
+      if (!NONJUMP_INSN_P (insn) || NEXT_INSN (insn))
+	add_note = true;
       else
 	{
-	  emit_move_insn (end_addr, GEN_INT (-rounded_size));
-	  insn = emit_insn (gen_add3_insn (end_addr, end_addr,
-					   stack_pointer_rtx));
-	  /* Describe the effect of INSN to the CFI engine.  */
-	  add_reg_note (insn, REG_FRAME_RELATED_EXPR,
-			gen_rtx_SET (end_addr,
-				     gen_rtx_PLUS (Pmode, stack_pointer_rtx,
-						   rs)));
+	  rtx set = single_set (insn);
+	  if (set == NULL_RTX
+	      || SET_DEST (set) != end_addr
+	      || GET_CODE (SET_SRC (set)) != PLUS
+	      || XEXP (SET_SRC (set), 0) != stack_pointer_rtx
+	      || XEXP (SET_SRC (set), 1) != rs)
+	    add_note = true;
 	}
+      insn = emit_insn (insn);
+      /* Describe the effect of INSN to the CFI engine, unless it
+	 is a single insn that describes it itself.  */
+      if (add_note)
+	add_reg_note (insn, REG_FRAME_RELATED_EXPR,
+		      gen_rtx_SET (end_addr,
+				   gen_rtx_PLUS (Pmode, stack_pointer_rtx,
+						 rs)));
       RTX_FRAME_RELATED_P (insn) = 1;
 
       /* Emit the loop.  */
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index bec80b2a94f..0c21d75dc16 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2020-02-07  Jakub Jelinek  <jakub@redhat.com>
+
+	PR target/93122
+	* gcc.target/powerpc/pr93122.c: New test.
+
 2020-02-07  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	PR c++/89404
diff --git a/gcc/testsuite/gcc.target/powerpc/pr93122.c b/gcc/testsuite/gcc.target/powerpc/pr93122.c
new file mode 100644
index 00000000000..158e6788edb
--- /dev/null
+++ b/gcc/testsuite/gcc.target/powerpc/pr93122.c
@@ -0,0 +1,12 @@
+/* PR target/93122 */
+/* { dg-do compile { target lp64 } } */
+/* { dg-options "-fstack-clash-protection -mprefixed-addr -mfuture" } */
+
+void bar (char *);
+
+void
+foo (void)
+{
+  char s[4294967296];
+  bar (s);
+}