[gcc(refs/users/meissner/heads/work122)] Fix power10 fusion and -fstack-protector, PR target/105325

[Michael Meissner <meissner@gcc.gnu.org>]

https://gcc.gnu.org/g:7c642fe4c35062120128089a5665796b7e64cb84

commit 7c642fe4c35062120128089a5665796b7e64cb84
Author: Michael Meissner <meissner@linux.ibm.com>
Date:   Fri Jun 9 02:08:24 2023 -0400

    Fix power10 fusion and -fstack-protector, PR target/105325
    
    This patch fixes an issue where if you use the -fstack-protector and
    -mcpu=power10 options and you have a large stack frame, the GCC compiler will
    generate a LWA instruction with a large offset.
    
    There are several problems with the current GCC:
    
        1)  The constraints in fusion.md (generated by genfusion.pl) use "m" for LWA
            and LD, when they should use "YZ".
    
        2)  The calls to address_is_non_pfx_d_or_x doesn't work with lwa using
            SImode as the mode.  You need to pass in DImode instead of SImode.  This
            is to allow lwz to be treated differently than lwa.
    
    The fix is to modify genfusion.pl that it sets the "YZ" constraint instead of
    "m" for the ld and lwa instructions.  And to pass DImode to the
    address_is_non_pfx_d_or_x function for lwa.
    
    2023-06-08   Michael Meissner  <meissner@linux.ibm.com>
    
    gcc/
    
            * config/rs6000/genfusion.pl (gen_ld_cmpi_p10_one): Fix problems that
            allowed prefixed lwa to be generated.
            * config/rs6000/fusion.md: Regenerate.
    
    gcc/testsuite/
    
            * g++.target/powerpc/pr105325.C: New test.

Diff:
---
 gcc/config/rs6000/fusion.md                 | 25 +++++++++++++++----------
 gcc/config/rs6000/genfusion.pl              | 17 ++++++++++++++---
 gcc/testsuite/g++.target/powerpc/pr105325.C | 26 ++++++++++++++++++++++++++
 3 files changed, 55 insertions(+), 13 deletions(-)

diff --git a/gcc/config/rs6000/fusion.md b/gcc/config/rs6000/fusion.md
index d45fb138a70..20af9b66fcf 100644
--- a/gcc/config/rs6000/fusion.md
+++ b/gcc/config/rs6000/fusion.md
@@ -22,7 +22,7 @@
 ;; load mode is DI result mode is clobber compare mode is CC extend is none
 (define_insn_and_split "*ld_cmpdi_cr0_DI_clobber_CC_none"
   [(set (match_operand:CC 2 "cc_reg_operand" "=x")
-        (compare:CC (match_operand:DI 1 "ds_form_mem_operand" "m")
+        (compare:CC (match_operand:DI 1 "ds_form_mem_operand" "YZ")
                     (match_operand:DI 3 "const_m1_to_1_operand" "n")))
    (clobber (match_scratch:DI 0 "=r"))]
   "(TARGET_P10_FUSION)"
@@ -43,7 +43,7 @@
 ;; load mode is DI result mode is clobber compare mode is CCUNS extend is none
 (define_insn_and_split "*ld_cmpldi_cr0_DI_clobber_CCUNS_none"
   [(set (match_operand:CCUNS 2 "cc_reg_operand" "=x")
-        (compare:CCUNS (match_operand:DI 1 "ds_form_mem_operand" "m")
+        (compare:CCUNS (match_operand:DI 1 "ds_form_mem_operand" "YZ")
                        (match_operand:DI 3 "const_0_to_1_operand" "n")))
    (clobber (match_scratch:DI 0 "=r"))]
   "(TARGET_P10_FUSION)"
@@ -64,7 +64,7 @@
 ;; load mode is DI result mode is DI compare mode is CC extend is none
 (define_insn_and_split "*ld_cmpdi_cr0_DI_DI_CC_none"
   [(set (match_operand:CC 2 "cc_reg_operand" "=x")
-        (compare:CC (match_operand:DI 1 "ds_form_mem_operand" "m")
+        (compare:CC (match_operand:DI 1 "ds_form_mem_operand" "YZ")
                     (match_operand:DI 3 "const_m1_to_1_operand" "n")))
    (set (match_operand:DI 0 "gpc_reg_operand" "=r") (match_dup 1))]
   "(TARGET_P10_FUSION)"
@@ -85,7 +85,7 @@
 ;; load mode is DI result mode is DI compare mode is CCUNS extend is none
 (define_insn_and_split "*ld_cmpldi_cr0_DI_DI_CCUNS_none"
   [(set (match_operand:CCUNS 2 "cc_reg_operand" "=x")
-        (compare:CCUNS (match_operand:DI 1 "ds_form_mem_operand" "m")
+        (compare:CCUNS (match_operand:DI 1 "ds_form_mem_operand" "YZ")
                        (match_operand:DI 3 "const_0_to_1_operand" "n")))
    (set (match_operand:DI 0 "gpc_reg_operand" "=r") (match_dup 1))]
   "(TARGET_P10_FUSION)"
@@ -106,7 +106,7 @@
 ;; load mode is SI result mode is clobber compare mode is CC extend is none
 (define_insn_and_split "*lwa_cmpdi_cr0_SI_clobber_CC_none"
   [(set (match_operand:CC 2 "cc_reg_operand" "=x")
-        (compare:CC (match_operand:SI 1 "ds_form_mem_operand" "m")
+        (compare:CC (match_operand:SI 1 "ds_form_mem_operand" "YZ")
                     (match_operand:SI 3 "const_m1_to_1_operand" "n")))
    (clobber (match_scratch:SI 0 "=r"))]
   "(TARGET_P10_FUSION)"
@@ -114,13 +114,14 @@
   "&& reload_completed
    && (cc_reg_not_cr0_operand (operands[2], CCmode)
        || !address_is_non_pfx_d_or_x (XEXP (operands[1], 0),
-                                      SImode, NON_PREFIXED_DS))"
+                                      DImode, NON_PREFIXED_DS))"
   [(set (match_dup 0) (match_dup 1))
    (set (match_dup 2)
         (compare:CC (match_dup 0) (match_dup 3)))]
   ""
   [(set_attr "type" "fused_load_cmpi")
    (set_attr "cost" "8")
+   (set_attr "sign_extend" "yes")
    (set_attr "length" "8")])
 
 ;; load-cmpi fusion pattern generated by gen_ld_cmpi_p10
@@ -148,7 +149,7 @@
 ;; load mode is SI result mode is SI compare mode is CC extend is none
 (define_insn_and_split "*lwa_cmpdi_cr0_SI_SI_CC_none"
   [(set (match_operand:CC 2 "cc_reg_operand" "=x")
-        (compare:CC (match_operand:SI 1 "ds_form_mem_operand" "m")
+        (compare:CC (match_operand:SI 1 "ds_form_mem_operand" "YZ")
                     (match_operand:SI 3 "const_m1_to_1_operand" "n")))
    (set (match_operand:SI 0 "gpc_reg_operand" "=r") (match_dup 1))]
   "(TARGET_P10_FUSION)"
@@ -156,13 +157,14 @@
   "&& reload_completed
    && (cc_reg_not_cr0_operand (operands[2], CCmode)
        || !address_is_non_pfx_d_or_x (XEXP (operands[1], 0),
-                                      SImode, NON_PREFIXED_DS))"
+                                      DImode, NON_PREFIXED_DS))"
   [(set (match_dup 0) (match_dup 1))
    (set (match_dup 2)
         (compare:CC (match_dup 0) (match_dup 3)))]
   ""
   [(set_attr "type" "fused_load_cmpi")
    (set_attr "cost" "8")
+   (set_attr "sign_extend" "yes")
    (set_attr "length" "8")])
 
 ;; load-cmpi fusion pattern generated by gen_ld_cmpi_p10
@@ -190,7 +192,7 @@
 ;; load mode is SI result mode is EXTSI compare mode is CC extend is sign
 (define_insn_and_split "*lwa_cmpdi_cr0_SI_EXTSI_CC_sign"
   [(set (match_operand:CC 2 "cc_reg_operand" "=x")
-        (compare:CC (match_operand:SI 1 "ds_form_mem_operand" "m")
+        (compare:CC (match_operand:SI 1 "ds_form_mem_operand" "YZ")
                     (match_operand:SI 3 "const_m1_to_1_operand" "n")))
    (set (match_operand:EXTSI 0 "gpc_reg_operand" "=r") (sign_extend:EXTSI (match_dup 1)))]
   "(TARGET_P10_FUSION)"
@@ -198,13 +200,14 @@
   "&& reload_completed
    && (cc_reg_not_cr0_operand (operands[2], CCmode)
        || !address_is_non_pfx_d_or_x (XEXP (operands[1], 0),
-                                      SImode, NON_PREFIXED_DS))"
+                                      DImode, NON_PREFIXED_DS))"
   [(set (match_dup 0) (sign_extend:EXTSI (match_dup 1)))
    (set (match_dup 2)
         (compare:CC (match_dup 0) (match_dup 3)))]
   ""
   [(set_attr "type" "fused_load_cmpi")
    (set_attr "cost" "8")
+   (set_attr "sign_extend" "yes")
    (set_attr "length" "8")])
 
 ;; load-cmpi fusion pattern generated by gen_ld_cmpi_p10
@@ -247,6 +250,7 @@
   ""
   [(set_attr "type" "fused_load_cmpi")
    (set_attr "cost" "8")
+   (set_attr "sign_extend" "yes")
    (set_attr "length" "8")])
 
 ;; load-cmpi fusion pattern generated by gen_ld_cmpi_p10
@@ -289,6 +293,7 @@
   ""
   [(set_attr "type" "fused_load_cmpi")
    (set_attr "cost" "8")
+   (set_attr "sign_extend" "yes")
    (set_attr "length" "8")])
 
 ;; load-cmpi fusion pattern generated by gen_ld_cmpi_p10
diff --git a/gcc/config/rs6000/genfusion.pl b/gcc/config/rs6000/genfusion.pl
index 82e8f863b02..622ef211b4c 100755
--- a/gcc/config/rs6000/genfusion.pl
+++ b/gcc/config/rs6000/genfusion.pl
@@ -59,12 +59,15 @@ sub gen_ld_cmpi_p10_one
 
   my $np = "NON_PREFIXED_D";
   my $mempred = "non_update_memory_operand";
+  my $lmode_prefix_call = $lmode;
   my $extend;
 
   if ($ccmode eq "CC") {
-    # ld and lwa are both DS-FORM.
+    # ld and lwa are both DS-FORM.  lwa needs to use lwa_operand to properly
+    # reject prefixed addresses.
     ($lmode =~ /^[SD]I$/) and $np = "NON_PREFIXED_DS";
     ($lmode =~ /^[SD]I$/) and $mempred = "ds_form_mem_operand";
+    ($lmode eq "SI") and $lmode_prefix_call = "DI";
   } else {
     if ($lmode eq "DI") {
       # ld is DS-form, but lwz is not.
@@ -91,12 +94,13 @@ sub gen_ld_cmpi_p10_one
   }
 
   my $ldst = mode_to_ldst_char($lmode);
+  my $constraint = ($np eq "NON_PREFIXED_DS") ? "YZ" : "m";
   print <<HERE;
 ;; load-cmpi fusion pattern generated by gen_ld_cmpi_p10
 ;; load mode is $lmode result mode is $result compare mode is $ccmode extend is $extend
 (define_insn_and_split "*l${ldst}${echr}_cmp${cmpl}di_cr0_${lmode}_${result}_${ccmode}_${extend}"
   [(set (match_operand:${ccmode} 2 "cc_reg_operand" "=x")
-        (compare:${ccmode} (match_operand:${lmode} 1 "${mempred}" "m")
+        (compare:${ccmode} (match_operand:${lmode} 1 "${mempred}" "${constraint}")
 HERE
   print "   " if $ccmode eq "CCUNS";
 print <<HERE;
@@ -123,7 +127,7 @@ HERE
   "&& reload_completed
    && (cc_reg_not_cr0_operand (operands[2], CCmode)
        || !address_is_non_pfx_d_or_x (XEXP (operands[1], 0),
-                                      ${lmode}mode, ${np}))"
+                                      ${lmode_prefix_call}mode, ${np}))"
 HERE
 
   if ($extend eq "none") {
@@ -140,6 +144,13 @@ HERE
   ""
   [(set_attr "type" "fused_load_cmpi")
    (set_attr "cost" "8")
+HERE
+
+  if ($ccmode eq "CC" && $lmode ne "DI") {
+    print "   (set_attr \"sign_extend\" \"yes\")\n";
+  }
+
+  print <<HERE;
    (set_attr "length" "8")])
 
 HERE
diff --git a/gcc/testsuite/g++.target/powerpc/pr105325.C b/gcc/testsuite/g++.target/powerpc/pr105325.C
new file mode 100644
index 00000000000..d0e66a0b897
--- /dev/null
+++ b/gcc/testsuite/g++.target/powerpc/pr105325.C
@@ -0,0 +1,26 @@
+/* { dg-do assemble } */
+/* { dg-require-effective-target lp64 } */
+/* { dg-require-effective-target power10_ok } */
+/* { dg-require-effective-target powerpc_prefixed_addr } */
+/* { dg-options "-O2 -mdejagnu-cpu=power10 -fstack-protector" } */
+
+/* Test that power10 fusion does not generate an LWA/CMPDI instruction pair
+   instead of PLWZ/CMPWI.  Ultimately the code was dying because the fusion
+   load + compare -1/0/1 patterns did not handle the possibility that the load
+   might be prefixed.  The -fstack-protector option is needed to show the
+   bug.  */
+
+struct Ath__array1D {
+  int _current;
+  int getCnt() { return _current; }
+};
+struct extMeasure {
+  int _mapTable[10000];
+  Ath__array1D _metRCTable;
+};
+void measureRC() {
+  extMeasure m;
+  for (; m._metRCTable.getCnt();)
+    for (;;)
+      ;
+}