15.0.0: add revert of LRA patch

See https://inbox.sourceware.org/gcc-patches/CA+=Sn1=_jL5P1Nbx4b7O-wYttpMsP4N545nk49rXntKnoJ7G-Q@mail.gmail.com/.

It breaks arm64 bootstrap at least.

Signed-off-by: Sam James <sam@gentoo.org>

2 files changed, 102 insertions, 0 deletions

diff --git a/15.0.0/gentoo/32_all_Revert-lra-emit-caller-save-register-spills-before-c.patch b/15.0.0/gentoo/32_all_Revert-lra-emit-caller-save-register-spills-before-c.patch
new file mode 100644
index 0000000..6cd1b43
--- /dev/null
+++ b/15.0.0/gentoo/32_all_Revert-lra-emit-caller-save-register-spills-before-c.patch
@@ -0,0 +1,101 @@
+From c67cc1d712f488a93d03dcfcda70e82250e13ab9 Mon Sep 17 00:00:00 2001
+Message-ID: <c67cc1d712f488a93d03dcfcda70e82250e13ab9.1723231445.git.sam@gentoo.org>
+From: Sam James <sam@gentoo.org>
+Date: Fri, 9 Aug 2024 20:24:00 +0100
+Subject: [PATCH] Revert "lra: emit caller-save register spills before call
+ insn [PR116028]"
+
+This reverts commit 3c67a0fa1dd39a3378deb854a7fef0ff7fe38004.
+
+See https://inbox.sourceware.org/gcc-patches/CA+=Sn1=_jL5P1Nbx4b7O-wYttpMsP4N545nk49rXntKnoJ7G-Q@mail.gmail.com/.
+---
+ gcc/lra-constraints.cc                       | 28 +++-----------------
+ gcc/testsuite/gcc.dg/ira-shrinkwrap-prep-1.c |  2 +-
+ gcc/testsuite/gcc.dg/pr10474.c               |  2 +-
+ 3 files changed, 6 insertions(+), 26 deletions(-)
+
+diff --git a/gcc/lra-constraints.cc b/gcc/lra-constraints.cc
+index 28c1a877c003..92b343fa99a0 100644
+--- a/gcc/lra-constraints.cc
++++ b/gcc/lra-constraints.cc
+@@ -152,9 +152,6 @@ static machine_mode curr_operand_mode[MAX_RECOG_OPERANDS];
+    (e.g. constant) and whose subreg is given operand of the current
+    insn.  VOIDmode in all other cases.  */
+ static machine_mode original_subreg_reg_mode[MAX_RECOG_OPERANDS];
+-/* The nearest call insn for an insn on which split transformation
+-   will be done. The call insn is in the same EBB as the insn.  */
+-static rtx_insn *latest_call_insn;
+ 
+ 
+ 
+@@ -6289,25 +6286,10 @@ split_reg (bool before_p, int original_regno, rtx_insn *insn,
+ 			 after_p ? restore : NULL,
+ 			 call_save_p
+ 			 ?  "Add reg<-save" : "Add reg<-split");
+-  if (call_save_p && latest_call_insn != NULL)
+-    /* PR116028: If original_regno is a pseudo that has been assigned a
+-       call-save hard register, then emit the spill insn before the call
+-       insn 'latest_call_insn' instead of adjacent to 'insn'. If 'insn'
+-       and 'latest_call_insn' belong to the same EBB but to two separate
+-       BBs, and if 'insn' is present in the entry BB, then generating the
+-       spill insn in the entry BB can prevent shrink wrap from happening.
+-       This is because the spill insn references the stack pointer and
+-       hence the prolog gets generated in the entry BB itself. It is
+-       also more efficient to generate the spill before
+-       'latest_call_insn' as the spill now occurs only in the path
+-       containing the call.  */
+-    lra_process_new_insns (PREV_INSN (latest_call_insn), NULL, save,
+-			   "Add save<-reg");
+-  else
+-    lra_process_new_insns (insn, before_p ? save : NULL,
+-			   before_p ? NULL : save,
+-			   call_save_p
+-			   ?  "Add save<-reg" : "Add split<-reg");
++  lra_process_new_insns (insn, before_p ? save : NULL,
++			 before_p ? NULL : save,
++			 call_save_p
++			 ?  "Add save<-reg" : "Add split<-reg");
+   if (nregs > 1 || original_regno < FIRST_PSEUDO_REGISTER)
+     /* If we are trying to split multi-register.  We should check
+        conflicts on the next assignment sub-pass.  IRA can allocate on
+@@ -6791,7 +6773,6 @@ inherit_in_ebb (rtx_insn *head, rtx_insn *tail)
+   last_processed_bb = NULL;
+   CLEAR_HARD_REG_SET (potential_reload_hard_regs);
+   live_hard_regs = eliminable_regset | lra_no_alloc_regs;
+-  latest_call_insn = NULL;
+   /* We don't process new insns generated in the loop.	*/
+   for (curr_insn = tail; curr_insn != PREV_INSN (head); curr_insn = prev_insn)
+     {
+@@ -7004,7 +6985,6 @@ inherit_in_ebb (rtx_insn *head, rtx_insn *tail)
+ 	      last_call_for_abi[callee_abi.id ()] = calls_num;
+ 	      full_and_partial_call_clobbers
+ 		|= callee_abi.full_and_partial_reg_clobbers ();
+-	      latest_call_insn = curr_insn;
+ 	      if ((cheap = find_reg_note (curr_insn,
+ 					  REG_RETURNED, NULL_RTX)) != NULL_RTX
+ 		  && ((cheap = XEXP (cheap, 0)), true)
+diff --git a/gcc/testsuite/gcc.dg/ira-shrinkwrap-prep-1.c b/gcc/testsuite/gcc.dg/ira-shrinkwrap-prep-1.c
+index 8c150972f952..a95637abbe54 100644
+--- a/gcc/testsuite/gcc.dg/ira-shrinkwrap-prep-1.c
++++ b/gcc/testsuite/gcc.dg/ira-shrinkwrap-prep-1.c
+@@ -26,4 +26,4 @@ bar (long a)
+ 
+ /* { dg-final { scan-rtl-dump "Will split live ranges of parameters" "ira" } } */
+ /* { dg-final { scan-rtl-dump "Split live-range of register" "ira" { xfail { ! aarch64*-*-* } } } } */
+-/* { dg-final { scan-rtl-dump "Performing shrink-wrapping" "pro_and_epilogue" } } */
++/* { dg-final { scan-rtl-dump "Performing shrink-wrapping" "pro_and_epilogue" { xfail powerpc*-*-* } } } */
+diff --git a/gcc/testsuite/gcc.dg/pr10474.c b/gcc/testsuite/gcc.dg/pr10474.c
+index b5393d5b6e3e..a4af536ec284 100644
+--- a/gcc/testsuite/gcc.dg/pr10474.c
++++ b/gcc/testsuite/gcc.dg/pr10474.c
+@@ -13,4 +13,4 @@ void f(int *i)
+ }
+ 
+ /* XFAIL due to PR70681.  */ 
+-/* { dg-final { scan-rtl-dump "Performing shrink-wrapping" "pro_and_epilogue"  { xfail arm*-*-* } } } */
++/* { dg-final { scan-rtl-dump "Performing shrink-wrapping" "pro_and_epilogue"  { xfail arm*-*-* powerpc*-*-* } } } */
+
+base-commit: 9e4da946c4263a4c89d5fc365b3c97ae244c5018
+-- 
+2.45.2
+
diff --git a/15.0.0/gentoo/README.history b/15.0.0/gentoo/README.history
index a872a71..3c55551 100644
--- a/15.0.0/gentoo/README.history
+++ b/15.0.0/gentoo/README.history
@@ -1,6 +1,7 @@
 ?	????
 
 	- 78_all_gcc_don-t-enable-fext-dce-with-O2-for-now.patch
+	+ 32_all_Revert-lra-emit-caller-save-register-spills-before-c.patch
 
 8	5 August 2024