From: Andrew Stubbs <ams@baylibre.com>
Date: Fri, 28 Jun 2024 10:47:50 +0000 (+0000)
Subject: amdgcn: Fix RDNA V32 permutations [PR115640]
X-Git-Tag: basepoints/gcc-16~7848
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ef0b30212f7756db15d7507bfd871bf377d7d648;p=thirdparty%2Fgcc.git

amdgcn: Fix RDNA V32 permutations [PR115640]

There was an off-by-one error in the RDNA validation check, plus I forgot to
allow for two-to-one permute-and-merge operations.

	PR target/115640

gcc/ChangeLog:

	* config/gcn/gcn.cc (gcn_vectorize_vec_perm_const): Modify RDNA checks.
---

diff --git a/gcc/config/gcn/gcn.cc b/gcc/config/gcn/gcn.cc
index d6531f55190..aab9b59c519 100644
--- a/gcc/config/gcn/gcn.cc
+++ b/gcc/config/gcn/gcn.cc
@@ -5134,7 +5134,7 @@ gcn_vectorize_vec_perm_const (machine_mode vmode, machine_mode op_mode,
      Reject permutations that cross the boundary.  */
   if (TARGET_RDNA2_PLUS)
     for (unsigned int i = 0; i < nelt; i++)
-      if (i < 31 ? perm[i] > 31 : perm[i] < 32)
+      if (i < 32 ? (perm[i] % nelt) > 31 : (perm[i] % nelt) < 32)
 	return false;
 
   /* All vector permutations are possible on other architectures,