diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 5e8ee54c3494ff5a705d38aab81d591fd4995ca9..535f956d2c0d24482e5f904689f1985a2cf97b47 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -141,12 +141,24 @@ package:gcc-solaris-linux-x86_64-cross-sunos-i386:
     script:
         - gcc-solaris/package-linux.bash i386 > gcc-i386.log 2>&1
 
+package:gcc-solaris-linux-x86_64-cross-sunos-x86_64:
+    extends:
+        - .package:gcc_solaris
+    script:
+        - gcc-solaris/package-linux.bash x86_64 > gcc-x86_64.log 2>&1
+
 package:gcc-solaris-linux-x86_64-cross-sunos-sparc:
     extends:
         - .package:gcc_solaris
     script:
         - gcc-solaris/package-linux.bash sparc > gcc-sparc.log 2>&1
 
+package:gcc-solaris-linux-x86_64-cross-sunos-sparc64:
+    extends:
+        - .package:gcc_solaris
+    script:
+        - gcc-solaris/package-linux.bash sparc64 > gcc-sparc64.log 2>&1
+
 upload:gcc-solaris:
     extends:
         - .upload_job
@@ -154,7 +166,9 @@ upload:gcc-solaris:
         - .rules
     needs:
         - package:gcc-solaris-linux-x86_64-cross-sunos-i386
+        - package:gcc-solaris-linux-x86_64-cross-sunos-x86_64
         - package:gcc-solaris-linux-x86_64-cross-sunos-sparc
+        - package:gcc-solaris-linux-x86_64-cross-sunos-sparc64
     variables:
         UPLOAD_FILES: gcc-*-cross-sunos-*.tar.xz
 
@@ -165,7 +179,9 @@ release:gcc-solaris:
         - .rules
     needs:
         - package:gcc-solaris-linux-x86_64-cross-sunos-i386
+        - package:gcc-solaris-linux-x86_64-cross-sunos-x86_64
         - package:gcc-solaris-linux-x86_64-cross-sunos-sparc
+        - package:gcc-solaris-linux-x86_64-cross-sunos-sparc64
         - job: upload:gcc-solaris
           artifacts: false
 
diff --git a/.gitlab/ci/make-release.sh b/.gitlab/ci/make-release.sh
index 4852e798403921703f3b375e96767d77e0ebafd2..8697942551bc4fc7ef032e59de0b023bdba98fc2 100755
--- a/.gitlab/ci/make-release.sh
+++ b/.gitlab/ci/make-release.sh
@@ -50,13 +50,19 @@ case "$CI_COMMIT_TAG" in
     gcc-solaris/v*)
         # Asset discovery.
         linux_x86_64_cross_sunos_i386="$( ls gcc-*-linux-x86_64-cross-sunos-i386.tar.xz )"
+        linux_x86_64_cross_sunos_x86_64="$( ls gcc-*-linux-x86_64-cross-sunos-x86_64.tar.xz )"
         linux_x86_64_cross_sunos_sparc="$( ls gcc-*-linux-x86_64-cross-sunos-sparc.tar.xz )"
+        linux_x86_64_cross_sunos_sparc64="$( ls gcc-*-linux-x86_64-cross-sunos-sparc64.tar.xz )"
         readonly linux_x86_64_cross_sunos_i386
+        readonly linux_x86_64_cross_sunos_x86_64
         readonly linux_x86_64_cross_sunos_sparc
+        readonly linux_x86_64_cross_sunos_sparc64
 
         make_release \
             --assets-link "{\"name\":\"$CI_COMMIT_TAG Linux x86_64 cross to SunOS i386\",\"url\":\"$urlbase/$linux_x86_64_cross_sunos_i386\"}" \
-            --assets-link "{\"name\":\"$CI_COMMIT_TAG Linux x86_64 cross to SunOS sparc\",\"url\":\"$urlbase/$linux_x86_64_cross_sunos_sparc\"}"
+            --assets-link "{\"name\":\"$CI_COMMIT_TAG Linux x86_64 cross to SunOS x86_64\",\"url\":\"$urlbase/$linux_x86_64_cross_sunos_x86_64\"}" \
+            --assets-link "{\"name\":\"$CI_COMMIT_TAG Linux x86_64 cross to SunOS sparc\",\"url\":\"$urlbase/$linux_x86_64_cross_sunos_sparc\"}" \
+            --assets-link "{\"name\":\"$CI_COMMIT_TAG Linux x86_64 cross to SunOS sparc64\",\"url\":\"$urlbase/$linux_x86_64_cross_sunos_sparc64\"}"
         ;;
     gfortran-macos/v*)
         # Asset discovery.
diff --git a/gcc-solaris/package-linux.bash b/gcc-solaris/package-linux.bash
index 282850a0f74a2a457c2faaf6cdfdb9693f5a8984..0458a0c259f3eddb8dc069a26219b219ae91430f 100755
--- a/gcc-solaris/package-linux.bash
+++ b/gcc-solaris/package-linux.bash
@@ -8,14 +8,36 @@ readonly arch
 case "$arch" in
     i386)
         target=i386-pc-solaris2.10
+        lib_arch32=
+        lib_arch64=/amd64
+        lib_arch_default=$lib_arch32
         sysroot_tarball="sysroot-i386-pc-solaris2.10-sunos5.10-1.tar.xz"
         sysroot_sha256sum="1b9251699f4e412ba5b0fde9c0fb96ceef6b8a1f47f0c1f2146ba0ba9da458b8"
         ;;
+    x86_64)
+        target=x86_64-pc-solaris2.10
+        lib_arch32=
+        lib_arch64=/amd64
+        lib_arch_default=$lib_arch64
+        sysroot_tarball="sysroot-x86_64-pc-solaris2.10-sunos5.10-1.tar.xz"
+        sysroot_sha256sum="bea632b3ae755f89a1c0e64775437a9b29001a3fc3a3c2c6247b921776059231"
+        ;;
     sparc)
         target=sparc-sun-solaris2.10
+        lib_arch32=
+        lib_arch64=/sparcv9
+        lib_arch_default=$lib_arch32
         sysroot_tarball="sysroot-sparc-sun-solaris2.10-sunos5.10-1.tar.xz"
         sysroot_sha256sum="e6c668a63dc00de443d07cbe2be779335642ffe1b818ba85d23ab543982aaf23"
         ;;
+    sparc64)
+        target=sparc64-sun-solaris2.10
+        lib_arch32=
+        lib_arch64=/sparcv9
+        lib_arch_default=$lib_arch64
+        sysroot_tarball="sysroot-sparc64-sun-solaris2.10-sunos5.10-1.tar.xz"
+        sysroot_sha256sum="fd60cc1be951ae314ff2b4246ac055c8e5b21c39b4cd41b23ebcec709451d90f"
+        ;;
     *)
         echo >&2 "Unknown architecture: $arch"
         exit 1
@@ -92,7 +114,11 @@ popd
 readonly gcc="/opt/cross/bin/$target-gcc"
 readonly specs="$(dirname $("$gcc" -print-libgcc-file-name))/specs"
 "$gcc" -dumpspecs > "$specs"
-sed -i '/^\*link:$/ {n;s|$| -rpath-link /opt/cross/sysroot/'"$target"'/usr/lib -rpath-link /opt/cross/sysroot/'"$target"'/lib|}' "$specs"
+sed -i '
+  /^\*link_arch32:$/ {n;s|$| -rpath-link %R/usr/lib'"$lib_arch32"' -rpath-link %R/lib'"$lib_arch32"'|}
+  /^\*link_arch64:$/ {n;s|$| -rpath-link %R/usr/lib'"$lib_arch64"' -rpath-link %R/lib'"$lib_arch64"'|}
+  /^\*link_arch_default:$/ {n;s|$| -rpath-link %R/usr/lib'"$lib_arch_default"' -rpath-link %R/lib'"$lib_arch_default"'|}
+' "$specs"
 
 cat >"/opt/cross/README.$target" <<EOF
 Populate the sysroot:
diff --git a/gcc-solaris/sysroot-paths.bash b/gcc-solaris/sysroot-paths.bash
index d6e44ffa5033c7e384cbc6efa01be4b86493002e..e89238bb49abd8593c0584f5124ff9d639f65b07 100755
--- a/gcc-solaris/sysroot-paths.bash
+++ b/gcc-solaris/sysroot-paths.bash
@@ -17,6 +17,8 @@ pkg_fmri_urls='
   http://pkg.oracle.com/solaris/release/manifest/0/system/library/security/crypto@11.4,5.11-11.4.42.0.0.111.1:20211203T214125Z
   http://pkg.oracle.com/solaris/release/manifest/0/system/linker@11.4-11.4.0.0.1.15.0:20180817T003258Z
   http://pkg.oracle.com/solaris/release/manifest/0/system/linker@11.4,5.11-11.4.42.0.0.111.1:20211203T214307Z
+  http://pkg.oracle.com/solaris/release/manifest/0/library/zlib@1.2.11,11.4-11.4.42.0.0.111.0:20211203T203816Z
+  http://pkg.oracle.com/solaris/release/manifest/0/library/zlib@1.2.11,5.11-11.4.0.0.1.14.0:20180814T170708Z
 '
 
 # Fetch package manifests and parse out a list of relevant paths.
diff --git a/gcc-solaris/sysroot-paths.lst b/gcc-solaris/sysroot-paths.lst
index b95969a73314ea36514537ef0d704402af75c1a7..7444d1b08ad31930b2b91707e2075231d12ab30f 100644
--- a/gcc-solaris/sysroot-paths.lst
+++ b/gcc-solaris/sysroot-paths.lst
@@ -168,6 +168,8 @@ lib/amd64/libxnet.so
 lib/amd64/libxnet.so.1
 lib/amd64/libxprop.so
 lib/amd64/libxprop.so.1
+lib/amd64/libz.so
+lib/amd64/libz.so.1
 lib/amd64/nss_dns.so.1
 lib/amd64/nss_files.so.1
 lib/amd64/nss_nis.so.1
@@ -333,6 +335,8 @@ lib/libxnet.so
 lib/libxnet.so.1
 lib/libxprop.so
 lib/libxprop.so.1
+lib/libz.so
+lib/libz.so.1
 lib/nss_dns.so.1
 lib/nss_files.so.1
 lib/nss_nis.so.1
@@ -506,6 +510,8 @@ lib/sparcv9/libxnet.so
 lib/sparcv9/libxnet.so.1
 lib/sparcv9/libxprop.so
 lib/sparcv9/libxprop.so.1
+lib/sparcv9/libz.so
+lib/sparcv9/libz.so.1
 lib/sparcv9/nss_dns.so.1
 lib/sparcv9/nss_files.so.1
 lib/sparcv9/nss_nis.so.1
@@ -2098,6 +2104,8 @@ usr/include/wordexp.h
 usr/include/xpol.h
 usr/include/xti.h
 usr/include/xti_inet.h
+usr/include/zconf.h
+usr/include/zlib.h
 usr/include/zone.h
 usr/include/zonestat.h
 usr/lib/0@0.so.1
@@ -2353,6 +2361,8 @@ usr/lib/amd64/libxprop.so
 usr/lib/amd64/libxprop.so.1
 usr/lib/amd64/libzoneinfo.so
 usr/lib/amd64/libzoneinfo.so.1
+usr/lib/amd64/libz.so
+usr/lib/amd64/libz.so.1
 usr/lib/amd64/nss_ad.so.1
 usr/lib/amd64/nss_dns.so.1
 usr/lib/amd64/nss_files.so.1
@@ -2360,6 +2370,7 @@ usr/lib/amd64/nss_ldap.so.1
 usr/lib/amd64/nss_nis.so.1
 usr/lib/amd64/passwdutil.so.1
 usr/lib/amd64/pkgconfig/uuid.pc
+usr/lib/amd64/pkgconfig/zlib.pc
 usr/lib/amd64/straddr.so
 usr/lib/amd64/straddr.so.2
 usr/lib/amd64/values-Xa.o
@@ -2629,6 +2640,8 @@ usr/lib/libxnet.so
 usr/lib/libxnet.so.1
 usr/lib/libzoneinfo.so
 usr/lib/libzoneinfo.so.1
+usr/lib/libz.so
+usr/lib/libz.so.1
 usr/lib/mdb/proc/amd64/ld.so
 usr/lib/mdb/proc/ld.so
 usr/lib/mdb/proc/sparcv9/ld.so
@@ -2639,6 +2652,7 @@ usr/lib/nss_ldap.so.1
 usr/lib/nss_nis.so.1
 usr/lib/passwdutil.so.1
 usr/lib/pkgconfig/uuid.pc
+usr/lib/pkgconfig/zlib.pc
 usr/lib/sparcv9/0@0.so.1
 usr/lib/sparcv9/crt1.o
 usr/lib/sparcv9/crti.o
@@ -2887,6 +2901,8 @@ usr/lib/sparcv9/libxprop.so
 usr/lib/sparcv9/libxprop.so.1
 usr/lib/sparcv9/libzoneinfo.so
 usr/lib/sparcv9/libzoneinfo.so.1
+usr/lib/sparcv9/libz.so
+usr/lib/sparcv9/libz.so.1
 usr/lib/sparcv9/nss_ad.so.1
 usr/lib/sparcv9/nss_dns.so.1
 usr/lib/sparcv9/nss_files.so.1
@@ -2894,6 +2910,7 @@ usr/lib/sparcv9/nss_ldap.so.1
 usr/lib/sparcv9/nss_nis.so.1
 usr/lib/sparcv9/passwdutil.so.1
 usr/lib/sparcv9/pkgconfig/uuid.pc
+usr/lib/sparcv9/pkgconfig/zlib.pc
 usr/lib/sparcv9/straddr.so
 usr/lib/sparcv9/straddr.so.2
 usr/lib/sparcv9/values-Xa.o
diff --git a/gcc-solaris/sysroot.md b/gcc-solaris/sysroot.md
index 4cb9ff49929f0771841dd7003441a23fac06668f..3a2a6f8b646a0d326448542c324d5ca8d366456d 100644
--- a/gcc-solaris/sysroot.md
+++ b/gcc-solaris/sysroot.md
@@ -11,13 +11,17 @@ The list has already been recorded in an adjacent file.
 Copy the relevant paths from Solaris hosts:
 
 ```console
-$ ./sysroot-rsync.bash SOME-sunos5.10-i386-HOST:/  i386-pc-solaris2.10   --rsync-path=/opt/csw/bin/rsync
-$ ./sysroot-rsync.bash SOME-sunos5.10-sparc-HOST:/ sparc-sun-solaris2.10 --rsync-path=/opt/csw/bin/rsync
+$ ./sysroot-rsync.bash SOME-sunos5.10-i386-HOST:/    i386-pc-solaris2.10     --rsync-path=/opt/csw/bin/rsync
+$ ./sysroot-rsync.bash SOME-sunos5.10-x86_64-HOST:/  x86_64-pc-solaris2.10   --rsync-path=/opt/csw/bin/rsync
+$ ./sysroot-rsync.bash SOME-sunos5.10-sparc-HOST:/   sparc-sun-solaris2.10   --rsync-path=/opt/csw/bin/rsync
+$ ./sysroot-rsync.bash SOME-sunos5.10-sparc64-HOST:/ sparc64-sun-solaris2.10 --rsync-path=/opt/csw/bin/rsync
 ```
 
 Create the tarballs:
 
 ```console
-$ tar cJf sysroot-i386-pc-solaris2.10-sunos5.10-1.tar.xz   sysroot/i386-pc-solaris2.10/*
-$ tar cJf sysroot-sparc-sun-solaris2.10-sunos5.10-1.tar.xz sysroot/sparc-sun-solaris2.10/*
+$ tar cJf sysroot-i386-pc-solaris2.10-sunos5.10-1.tar.xz     sysroot/i386-pc-solaris2.10/*
+$ tar cJf sysroot-x86_64-pc-solaris2.10-sunos5.10-1.tar.xz   sysroot/x86_64-pc-solaris2.10/*
+$ tar cJf sysroot-sparc-sun-solaris2.10-sunos5.10-1.tar.xz   sysroot/sparc-sun-solaris2.10/*
+$ tar cJf sysroot-sparc64-sun-solaris2.10-sunos5.10-1.tar.xz sysroot/sparc64-sun-solaris2.10/*
 ```