diff --git a/Makefile.in b/Makefile.in
index ad3e84cd8e28..21d5ad3e9721 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -314,10 +314,6 @@ endif
 else
 ifdef CLANG_CL
 maybe_clobber_profiledbuild: clean
-# 32-bit PGO is currently blocked by bug 1479800
-ifeq ($(CPU_ARCH),x86_64)
-	$(LLVM_PROFDATA) merge -o $(DEPTH)/merged.profdata $(DEPTH)/*.profraw
-endif
 else
 maybe_clobber_profiledbuild:
 	$(RM) $(DIST)/bin/*.pgc
diff --git a/build/moz.configure/toolchain.configure b/build/moz.configure/toolchain.configure
index 5d74de7d20bd..272547fe535f 100755
--- a/build/moz.configure/toolchain.configure
+++ b/build/moz.configure/toolchain.configure
@@ -1240,14 +1240,10 @@ set_config('WRAP_SYSTEM_INCLUDES', wrap_system_includes)
 set_config('VISIBILITY_FLAGS', visibility_flags)
 
 
-@depends(c_compiler, check_build_environment, target)
+@depends(c_compiler)
 @imports('multiprocessing')
 @imports(_from='__builtin__', _import='min')
-def pgo_flags(compiler, build_env, target):
-    topobjdir = build_env.topobjdir
-    if topobjdir.endswith('/js/src'):
-        topobjdir = topobjdir[:-7]
-
+def pgo_flags(compiler):
     if compiler.type in ('gcc', 'clang'):
         return namespace(
             gen_cflags=['-fprofile-generate'],
@@ -1257,18 +1253,6 @@ def pgo_flags(compiler, build_env, target):
             use_ldflags=['-fprofile-use'],
         )
 
-    if compiler.type == 'clang-cl':
-        profdata = os.path.join(topobjdir, 'merged.profdata')
-        # 32-bit PGO is currently blocked by bug 1479800
-        if target.cpu == 'x86_64':
-          return namespace(
-              gen_cflags=['-fprofile-instr-generate'],
-              gen_ldflags=['clang_rt.profile-x86_64.lib'],
-              use_cflags=['-fprofile-instr-use=%s' % profdata,
-                          '-Wno-error=profile-instr-unprofiled'],
-              use_ldflags=[],
-          )
-
     if compiler.type == 'msvc':
         num_cores = min(8, multiprocessing.cpu_count())
         cgthreads = '-CGTHREADS:%s' % num_cores
@@ -1298,11 +1282,6 @@ set_config('PROFILE_GEN_LDFLAGS', pgo_flags.gen_ldflags)
 set_config('PROFILE_USE_CFLAGS', pgo_flags.use_cflags)
 set_config('PROFILE_USE_LDFLAGS', pgo_flags.use_ldflags)
 
-llvm_profdata = check_prog('LLVM_PROFDATA', ['llvm-profdata'],
-                           allow_missing=True)
-
-add_old_configure_assignment('LLVM_PROFDATA', llvm_profdata)
-
 
 @depends(c_compiler)
 def preprocess_option(compiler):
diff --git a/build/mozconfig.clang-cl b/build/mozconfig.clang-cl
index 96ba27014381..3ab9401d2f93 100644
--- a/build/mozconfig.clang-cl
+++ b/build/mozconfig.clang-cl
@@ -1,13 +1,8 @@
 if test -d "$topsrcdir/clang/bin"; then
     CLANG_DIR=`cd "$topsrcdir/clang/bin" ; pwd`
     export PATH="${CLANG_DIR}:${PATH}"
-    mk_export_correct_style PATH
-fi
 
-if test -d "$topsrcdir/clang/lib/clang"; then
-    CLANG_LIB_DIR="$(cd $topsrcdir/clang/lib/clang/* && cd lib/windows && pwd)"
-    export LIB=$LIB:$CLANG_LIB_DIR
-    mk_export_correct_style LIB
+    mk_export_correct_style PATH
 fi
 
 export CC=clang-cl