From: Roger Sayle <roger@nextmovesoftware.com>
Date: Tue, 24 Aug 2021 21:07:41 +0000 (+0100)
Subject: [Committed] PR middle-end/102031: Fix typo/mistake in simplify_truncation patch.
X-Git-Tag: upstream/12.2.0~5567
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=81e1894456bc6214c0c42148ff2b1bed142a3545;p=platform%2Fupstream%2Fgcc.git

[Committed] PR middle-end/102031: Fix typo/mistake in simplify_truncation patch.

My apologies again.  My patch to simplify truncations of SUBREGs in
simplify-rtx.c contained an error where I'd accidentally compared
against a mode instead of the precision of that mode.  Grr!  It even
survived regression testing on two platforms.  Fixed below, and
committed as obvious, after a full "make bootstrap" and "make -k check"
on x86_64-pc-linux-gnu with no new regressions.

2021-08-24  Roger Sayle  <roger@nextmovesoftware.com>

gcc/ChangeLog
	PR middle-end/102031
	* simplify-rtx.c (simplify_truncation): When comparing precisions
	use "subreg_prec" variable, not "subreg_mode".
---

diff --git a/gcc/simplify-rtx.c b/gcc/simplify-rtx.c
index 8eea9fb..c81e27e 100644
--- a/gcc/simplify-rtx.c
+++ b/gcc/simplify-rtx.c
@@ -841,7 +841,7 @@ simplify_context::simplify_truncation (machine_mode mode, rtx op,
 	{
 	  unsigned int int_op_prec = GET_MODE_PRECISION (int_op_mode);
 	  unsigned int subreg_prec = GET_MODE_PRECISION (subreg_mode);
-	  if (int_op_prec > subreg_mode)
+	  if (int_op_prec > subreg_prec)
 	    {
 	      if (int_mode == subreg_mode)
 		return SUBREG_REG (op);
@@ -851,7 +851,7 @@ simplify_context::simplify_truncation (machine_mode mode, rtx op,
 	    }
 	  /* Simplification of (truncate:A (subreg:B X:C 0)) where
  	     A is narrower than B and B is narrower than C.  */
-	  else if (int_op_prec < subreg_mode
+	  else if (int_op_prec < subreg_prec
 		   && GET_MODE_PRECISION (int_mode) < int_op_prec)
 	    return simplify_gen_unary (TRUNCATE, int_mode,
 				       SUBREG_REG (op), subreg_mode);