From 0312d11be3f666a6b71461dc8a09e7aac64853eb Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Thu, 20 Feb 2025 15:23:05 +0800
Subject: [PATCH] Revert "i386: Simplify PARALLEL RTX scan in
 ix86_find_all_reg_use"

This reverts commit 565d4e755498ad2b5ed55e368ef61eb9511cda3a.
---
 gcc/config/i386/i386.cc | 28 +++++++++++++++++++++++++---
 1 file changed, 25 insertions(+), 3 deletions(-)

diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc
index 560e6525b56..fafd4a511a3 100644
--- a/gcc/config/i386/i386.cc
+++ b/gcc/config/i386/i386.cc
@@ -8538,9 +8538,31 @@ ix86_find_all_reg_use (HARD_REG_SET &stack_slot_access,
       for (int i = 0; i < XVECLEN (pat, 0); i++)
 	{
 	  rtx exp = XVECEXP (pat, 0, i);
-
-	  if (GET_CODE (exp) == SET)
-	    ix86_find_all_reg_use_1 (exp, stack_slot_access, worklist);
+	  switch (GET_CODE (exp))
+	    {
+	    case ASM_OPERANDS:
+	    case CLOBBER:
+	    case PREFETCH:
+	    case USE:
+	      break;
+	    case UNSPEC:
+	    case UNSPEC_VOLATILE:
+	      for (int j = XVECLEN (exp, 0) - 1; j >= 0; j--)
+		{
+		  rtx x = XVECEXP (exp, 0, j);
+		  if (GET_CODE (x) == SET)
+		    ix86_find_all_reg_use_1 (x, stack_slot_access,
+					     worklist);
+		}
+	      break;
+	    case SET:
+	      ix86_find_all_reg_use_1 (exp, stack_slot_access,
+				       worklist);
+	      break;
+	    default:
+	      gcc_unreachable ();
+	      break;
+	    }
 	}
     }
 }
-- 
2.47.2