From 04da747a063850333b062e48d0531debe314dff9 Mon Sep 17 00:00:00 2001
From: Kewen Lin <linkw@linux.ibm.com>
Date: Tue, 23 Jul 2024 00:47:49 -0500
Subject: [PATCH] rs6000: Escalate warning to error for VSX with explicit
 no-altivec etc.

As the discussion in PR115688, for now when users specify
-mvsx and -mno-altivec explicitly, compiler emits warning
rather than error, but considering both options are given
explicitly, emitting hard error should be better.

So this patch is to escalate some related warning to error
when both are incompatible.

	PR target/115713

gcc/ChangeLog:

	* config/rs6000/rs6000.cc (rs6000_option_override_internal): Emit error
	messages when explicit VSX encounters explicit soft-float, no-altivec
	or avoid-indexed-addresses.

gcc/testsuite/ChangeLog:

	* gcc.target/powerpc/warn-1.c: Move to ...
	* gcc.target/powerpc/error-1.c: ... here.  Adjust dg-warning with
	dg-error and remove ineffective scan.
---
 gcc/config/rs6000/rs6000.cc                   | 43 +++++++++++--------
 .../powerpc/{warn-1.c => error-1.c}           |  3 +-
 2 files changed, 25 insertions(+), 21 deletions(-)
 rename gcc/testsuite/gcc.target/powerpc/{warn-1.c => error-1.c} (70%)

diff --git a/gcc/config/rs6000/rs6000.cc b/gcc/config/rs6000/rs6000.cc
index eddd2adbab5..019bb7ccc38 100644
--- a/gcc/config/rs6000/rs6000.cc
+++ b/gcc/config/rs6000/rs6000.cc
@@ -3830,32 +3830,37 @@ rs6000_option_override_internal (bool global_init_p)
   /* Add some warnings for VSX.  */
   if (TARGET_VSX)
     {
-      const char *msg = NULL;
+      bool explicit_vsx_p = rs6000_isa_flags_explicit & OPTION_MASK_VSX;
       if (!TARGET_HARD_FLOAT)
 	{
-	  if (rs6000_isa_flags_explicit & OPTION_MASK_VSX)
-	    msg = N_("%<-mvsx%> requires hardware floating point");
-	  else
+	  if (explicit_vsx_p)
 	    {
-	      rs6000_isa_flags &= ~ OPTION_MASK_VSX;
-	      rs6000_isa_flags_explicit |= OPTION_MASK_VSX;
+	      if (rs6000_isa_flags_explicit & OPTION_MASK_SOFT_FLOAT)
+		error ("%<-mvsx%> and %<-msoft-float%> are incompatible");
+	      else
+		warning (0, N_("%<-mvsx%> requires hardware floating-point"));
 	    }
+	  rs6000_isa_flags &= ~OPTION_MASK_VSX;
+	  rs6000_isa_flags_explicit |= OPTION_MASK_VSX;
 	}
       else if (TARGET_AVOID_XFORM > 0)
-	msg = N_("%<-mvsx%> needs indexed addressing");
-      else if (!TARGET_ALTIVEC && (rs6000_isa_flags_explicit
-				   & OPTION_MASK_ALTIVEC))
-        {
-	  if (rs6000_isa_flags_explicit & OPTION_MASK_VSX)
-	    msg = N_("%<-mvsx%> and %<-mno-altivec%> are incompatible");
-	  else
-	    msg = N_("%<-mno-altivec%> disables vsx");
-        }
-
-      if (msg)
 	{
-	  warning (0, msg);
-	  rs6000_isa_flags &= ~ OPTION_MASK_VSX;
+	  if (explicit_vsx_p && OPTION_SET_P (TARGET_AVOID_XFORM))
+	    error ("%<-mvsx%> and %<-mavoid-indexed-addresses%>"
+		   " are incompatible");
+	  else
+	    warning (0, N_("%<-mvsx%> needs indexed addressing"));
+	  rs6000_isa_flags &= ~OPTION_MASK_VSX;
+	  rs6000_isa_flags_explicit |= OPTION_MASK_VSX;
+	}
+      else if (!TARGET_ALTIVEC
+	       && (rs6000_isa_flags_explicit & OPTION_MASK_ALTIVEC))
+	{
+	  if (explicit_vsx_p)
+	    error ("%<-mvsx%> and %<-mno-altivec%> are incompatible");
+	  else
+	    warning (0, N_("%<-mno-altivec%> disables vsx"));
+	  rs6000_isa_flags &= ~OPTION_MASK_VSX;
 	  rs6000_isa_flags_explicit |= OPTION_MASK_VSX;
 	}
     }
diff --git a/gcc/testsuite/gcc.target/powerpc/warn-1.c b/gcc/testsuite/gcc.target/powerpc/error-1.c
similarity index 70%
rename from gcc/testsuite/gcc.target/powerpc/warn-1.c
rename to gcc/testsuite/gcc.target/powerpc/error-1.c
index 76ac0c4e26e..d38eba8bb8a 100644
--- a/gcc/testsuite/gcc.target/powerpc/warn-1.c
+++ b/gcc/testsuite/gcc.target/powerpc/error-1.c
@@ -3,7 +3,7 @@
 /* { dg-require-effective-target powerpc_vsx_ok } */
 /* { dg-options "-O -mvsx -mno-altivec" } */
 
-/* { dg-warning "'-mvsx' and '-mno-altivec' are incompatible" "" { target *-*-* } 0 } */
+/* { dg-error "'-mvsx' and '-mno-altivec' are incompatible" "" { target *-*-* } 0 } */
 
 double
 foo (double *x, double *y)
@@ -16,4 +16,3 @@ foo (double *x, double *y)
   return z[0] * z[1];
 }
 
-/* { dg-final { scan-assembler-not "xsadddp" } } */