From: Jim Wilson <wilson@gcc.gnu.org>
Date: Sun, 14 Aug 1994 23:01:37 +0000 (-0700)
Subject: (mark_used_regs): When adding REG_DEAD notes...
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=ab28041e5ae3798cefdefb5c9200b9daa5be4ffb;p=platform%2Fupstream%2Fgcc.git

(mark_used_regs): When adding REG_DEAD notes...

(mark_used_regs): When adding REG_DEAD notes, check for
the case where a multiple register hard reg overlaps a register
set by the insn.

From-SVN: r7921
---

diff --git a/gcc/flow.c b/gcc/flow.c
index cc77429..21d28c1 100644
--- a/gcc/flow.c
+++ b/gcc/flow.c
@@ -2403,6 +2403,16 @@ mark_used_regs (needed, live, x, final, insn)
 #endif
 		)
 	      {
+		/* Check for the case where the register dying partially
+		   overlaps the register set by this insn.  */
+		if (regno < FIRST_PSEUDO_REGISTER
+		    && HARD_REGNO_NREGS (regno, GET_MODE (x)) > 1)
+		  {
+		    int n = HARD_REGNO_NREGS (regno, GET_CODE (x));
+		    while (--n >= 0)
+		      some_needed |= dead_or_set_regno_p (insn, regno + n);
+		  }
+
 		/* If none of the words in X is needed, make a REG_DEAD
 		   note.  Otherwise, we must make partial REG_DEAD notes.  */
 		if (! some_needed)