diff --git a/gcc/go/gofrontend/MERGE b/gcc/go/gofrontend/MERGE
index 304c910b2d0..2cd7a0e94fe 100644
--- a/gcc/go/gofrontend/MERGE
+++ b/gcc/go/gofrontend/MERGE
@@ -1,4 +1,4 @@
-b5ab7b419d6328f5126ba8d6795280129eaf6e79
+54aacecc8167bfba8420cb7b245787ff80bde61b
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.
diff --git a/gcc/go/gofrontend/types.cc b/gcc/go/gofrontend/types.cc
index 52606261833..f6c104cef8a 100644
--- a/gcc/go/gofrontend/types.cc
+++ b/gcc/go/gofrontend/types.cc
@@ -12,6 +12,7 @@
 #include "gogo.h"
 #include "go-diagnostics.h"
 #include "go-encode-id.h"
+#include "go-sha1.h"
 #include "operator.h"
 #include "expressions.h"
 #include "statements.h"
@@ -2776,22 +2777,43 @@ Ptrmask::set_from(Gogo* gogo, Type* type, int64_t ptrsize, int64_t offset)
     }
 }
 
-// Return a symbol name for this ptrmask.  This is used to coalesce
-// identical ptrmasks, which are common.  The symbol name must use
-// only characters that are valid in symbols.  It's nice if it's
-// short.  We convert it to a string that uses only 32 characters,
-// avoiding digits and u and U.
-
+// Return a symbol name for this ptrmask. This is used to coalesce identical
+// ptrmasks, which are common. The symbol name must use only characters that are
+// valid in symbols. It's nice if it's short. For smaller ptrmasks, we convert
+// it to a string that uses only 32 characters, avoiding digits and u and U. For
+// longer pointer masks, apply the same process to the SHA1 digest of the bits,
+// so as to avoid pathologically long symbol names (see related Go issues #32083
+// and #11583 for more on this). To avoid collisions between the two encoding
+// schemes, use a prefix ("X") for the SHA form to disambiguate.
 std::string
 Ptrmask::symname() const
 {
+  const std::vector<unsigned char>* bits(&this->bits_);
+  std::vector<unsigned char> shabits;
+  std::string prefix;
+
+  if (this->bits_.size() > 128)
+    {
+      // Produce a SHA1 digest of the data.
+      Go_sha1_helper* sha1_helper = go_create_sha1_helper();
+      sha1_helper->process_bytes(&this->bits_[0], this->bits_.size());
+      std::string digest = sha1_helper->finish();
+      delete sha1_helper;
+
+      // Redirect the bits vector to the digest, and update the prefix.
+      prefix = "X";
+      for (char c : digest)
+        shabits.push_back((unsigned char) c);
+      bits = &shabits;
+    }
+
   const char chars[33] = "abcdefghijklmnopqrstvwxyzABCDEFG";
   go_assert(chars[32] == '\0');
-  std::string ret;
+  std::string ret(prefix);
   unsigned int b = 0;
   int remaining = 0;
-  for (std::vector<unsigned char>::const_iterator p = this->bits_.begin();
-       p != this->bits_.end();
+  for (std::vector<unsigned char>::const_iterator p = bits->begin();
+       p != bits->end();
        ++p)
     {
       b |= *p << remaining;