[PATCH] FALLTHRU markers for sse.md and some cleanups

[Jakub Jelinek <jakub@redhat.com>]

On Thu, Sep 29, 2016 at 06:21:13PM +0200, Marek Polacek wrote:
> On Tue, Sep 27, 2016 at 09:58:20PM +0200, Jakub Jelinek wrote:
> > On Tue, Sep 27, 2016 at 09:29:10PM +0200, Florian Weimer wrote:
> > > Not sure if I read this code correctly, but if we fall through from
> > > V32HImode, and we have TARGET_SSE2 set, we execute this code:
> > > 
> > >       tmp = "p<logic>";
> > >       ssesuffix = TARGET_AVX512VL ? "q" : "";
> > > 
> > > And not gcc_unreachable (), as is probably intended.
> > 
> > It really doesn't matter.
> > The instruction uses
> > (define_mode_iterator VI12_AVX_AVX512F
> >   [ (V64QI "TARGET_AVX512F") (V32QI "TARGET_AVX") V16QI
> >     (V32HI "TARGET_AVX512F") (V16HI "TARGET_AVX") V8HI])
> > iterator (and, after all, ix86_hard_regno_mode_ok should ensure the same),
> > which means V64QI/V32HI will only show up for TARGET_AVX512F, V32QI/V16HI
> > only for TARGET_AVX (which implies TARGET_SSE2), and the slightly
> > nonsensical
> > gcc_assert (TARGET_SSE2 || TARGET_AVX512VL);
> > before the switch (the  || TARGET_AVX512VL is pointless, because
> > TARGET_AVX512VL implies TARGET_SSE2 as well as TARGET_AVX2).
> > So, I'd go perhaps for (untested) following patch, first diff -up, followed
> > by diff -upb:
> 
> Looks good, are you going to test/commit it?  Or should I?

Here it is, bootstrapped/regtested on x86_64-linux and i686-linux, ok for
trunk?

2016-09-30  Jakub Jelinek  <jakub@redhat.com>

	* config/i386/sse.md (<mask_codefor><code><mode>): Add FALLTHRU
	comments.  Simplify asserts, remove unnecessary conditions.
	Formatting fixes.
	(*<code><mode>3): Likewise.

--- gcc/config/i386/sse.md.jj	2016-08-30 08:42:09.169067639 +0200
+++ gcc/config/i386/sse.md	2016-09-30 14:40:45.382959729 +0200
@@ -11393,41 +11393,40 @@ (define_insn "<mask_codefor><code><mode>
     {
     case MODE_XI:
       gcc_assert (TARGET_AVX512F);
+      /* FALLTHRU */
     case MODE_OI:
-      gcc_assert (TARGET_AVX2 || TARGET_AVX512VL);
+      gcc_assert (TARGET_AVX2);
+      /* FALLTHRU */
     case MODE_TI:
-      gcc_assert (TARGET_SSE2 || TARGET_AVX512VL);
+      gcc_assert (TARGET_SSE2);
       switch (<MODE>mode)
-      {
-        case V16SImode:
-        case V8DImode:
-          if (TARGET_AVX512F)
-          {
-            tmp = "p<logic><ssemodesuffix>";
-            break;
-          }
-        case V8SImode:
-        case V4DImode:
-        case V4SImode:
-        case V2DImode:
-          tmp = TARGET_AVX512VL ? "p<logic><ssemodesuffix>" : "p<logic>";
-          break;
-        default:
-          gcc_unreachable ();
-      }
+	{
+	case V16SImode:
+	case V8DImode:
+	  tmp = "p<logic><ssemodesuffix>";
+	  break;
+	case V8SImode:
+	case V4DImode:
+	case V4SImode:
+	case V2DImode:
+	  tmp = TARGET_AVX512VL ? "p<logic><ssemodesuffix>" : "p<logic>";
+	  break;
+	default:
+	  gcc_unreachable ();
+	}
       break;
 
-   case MODE_V8SF:
+    case MODE_V8SF:
       gcc_assert (TARGET_AVX);
-   case MODE_V4SF:
+    case MODE_V4SF:
       gcc_assert (TARGET_SSE);
       gcc_assert (!<mask_applied>);
       tmp = "<logic>ps";
       break;
 
-   default:
+    default:
       gcc_unreachable ();
-   }
+    }
 
   switch (which_alternative)
     {
@@ -11489,46 +11488,42 @@ (define_insn "*<code><mode>3"
     {
     case MODE_XI:
       gcc_assert (TARGET_AVX512F);
+      /* FALLTHRU */
     case MODE_OI:
-      gcc_assert (TARGET_AVX2 || TARGET_AVX512VL);
+      gcc_assert (TARGET_AVX2);
+      /* FALLTHRU */
     case MODE_TI:
-      gcc_assert (TARGET_SSE2 || TARGET_AVX512VL);
+      gcc_assert (TARGET_SSE2);
       switch (<MODE>mode)
-        {
-        case V64QImode:
-        case V32HImode:
-          if (TARGET_AVX512F)
-          {
-            tmp = "p<logic>";
-            ssesuffix = "q";
-            break;
-          }
-        case V32QImode:
-        case V16HImode:
-        case V16QImode:
-        case V8HImode:
-          if (TARGET_AVX512VL || TARGET_AVX2 || TARGET_SSE2)
-          {
-            tmp = "p<logic>";
-            ssesuffix = TARGET_AVX512VL ? "q" : "";
-            break;
-          }
-        default:
-          gcc_unreachable ();
-      }
+	{
+	case V64QImode:
+	case V32HImode:
+	  tmp = "p<logic>";
+	  ssesuffix = "q";
+	  break;
+	case V32QImode:
+	case V16HImode:
+	case V16QImode:
+	case V8HImode:
+	  tmp = "p<logic>";
+	  ssesuffix = TARGET_AVX512VL ? "q" : "";
+	  break;
+	default:
+	  gcc_unreachable ();
+	}
       break;
 
-   case MODE_V8SF:
+    case MODE_V8SF:
       gcc_assert (TARGET_AVX);
-   case MODE_V4SF:
+    case MODE_V4SF:
       gcc_assert (TARGET_SSE);
       tmp = "<logic>ps";
       ssesuffix = "";
       break;
 
-   default:
+    default:
       gcc_unreachable ();
-   }
+    }
 
   switch (which_alternative)
     {


	Jakub