From: Jakub Jelinek <jakub@redhat.com>
Date: Mon, 5 Mar 2018 22:13:58 +0000 (+0100)
Subject: re PR target/84700 (ICE on 32-bit BE powerpc targets w/ -misel -O1)
X-Git-Tag: basepoints/gcc-9~835
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9a25c5ce6e2677ae33ba489bd18335332f5e2560;p=thirdparty%2Fgcc.git

re PR target/84700 (ICE on 32-bit BE powerpc targets w/ -misel -O1)

	PR target/84700
	* combine.c (combine_simplify_rtx): Don't try to simplify if
	if_then_else_cond returned non-NULL, but either true_rtx or false_rtx
	are equal to x.

	* gcc.target/powerpc/pr84700.c: New test.

From-SVN: r258263
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 5630a84a949a..716e77abc99f 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2018-03-05  Jakub Jelinek  <jakub@redhat.com>
+
+	PR target/84700
+	* combine.c (combine_simplify_rtx): Don't try to simplify if
+	if_then_else_cond returned non-NULL, but either true_rtx or false_rtx
+	are equal to x.
+
 2018-03-05  Segher Boessenkool  <segher@kernel.crashing.org>
 
 	* config/rs6000/rs6000.c (rs6000_loop_align): Don't align tiny loops
diff --git a/gcc/combine.c b/gcc/combine.c
index ddea5b18fe07..a4efd11703cf 100644
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -5734,7 +5734,11 @@ combine_simplify_rtx (rtx x, machine_mode op0_mode, int in_dest,
 	  /* If everything is a comparison, what we have is highly unlikely
 	     to be simpler, so don't use it.  */
 	  && ! (COMPARISON_P (x)
-		&& (COMPARISON_P (true_rtx) || COMPARISON_P (false_rtx))))
+		&& (COMPARISON_P (true_rtx) || COMPARISON_P (false_rtx)))
+	  /* Similarly, if we end up with one of the expressions the same
+	     as the original, it is certainly not simpler.  */
+	  && ! rtx_equal_p (x, true_rtx)
+	  && ! rtx_equal_p (x, false_rtx))
 	{
 	  rtx cop1 = const0_rtx;
 	  enum rtx_code cond_code = simplify_comparison (NE, &cond, &cop1);
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 9f9afb0df129..ca2986b62210 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2018-03-05  Jakub Jelinek  <jakub@redhat.com>
+
+	PR target/84700
+	* gcc.target/powerpc/pr84700.c: New test.
+
 2018-03-05  Nathan Sidwell  <nathan@acm.org>
 
 	PR c++/84702
diff --git a/gcc/testsuite/gcc.target/powerpc/pr84700.c b/gcc/testsuite/gcc.target/powerpc/pr84700.c
new file mode 100644
index 000000000000..c89094a56d39
--- /dev/null
+++ b/gcc/testsuite/gcc.target/powerpc/pr84700.c
@@ -0,0 +1,12 @@
+/* PR target/84700 */
+/* { dg-do compile } */
+/* { dg-options "-O1 -misel" } */
+
+long long int
+foo (long long int x)
+{
+  long long int a = x < 2;
+  int b = a >= 0;
+
+  return a + ((x == 0) ? a : b);
+}