lto: Stream has_unroll flag during LTO [PR116140]

When #pragma GCC unroll is processed in
tree-cfg.cc:replace_loop_annotate_in_block, we set both the loop->unroll
field (which is currently streamed out and back in during LTO) but also
the cfun->has_unroll flag.

cfun->has_unroll, however, is not currently streamed during LTO.  This
patch fixes that.

Prior to this patch, loops marked with #pragma GCC unroll that would be
unrolled by RTL loop2_unroll in a non-LTO compilation didn't get
unrolled under LTO.

gcc/ChangeLog:

	PR libstdc++/116140
	* lto-streamer-in.cc (input_struct_function_base): Stream in
	fn->has_unroll.
	* lto-streamer-out.cc (output_struct_function_base): Stream out
	fn->has_unroll.

gcc/testsuite/ChangeLog:

	PR libstdc++/116140
	* g++.dg/ext/pragma-unroll-lambda-lto.C: New test.

diff --git a/gcc/lto-streamer-in.cc b/gcc/lto-streamer-in.cc
index 64f7580732808ea73c3e469cb9b5320ce489c579..9d0ec5d589c45d10c39c0144826d9aeeb9856454 100644 (file)
--- a/gcc/lto-streamer-in.cc
+++ b/gcc/lto-streamer-in.cc
@@ -1326,6 +1326,7 @@ input_struct_function_base (struct function *fn, class data_in *data_in,
   fn->has_force_vectorize_loops = bp_unpack_value (&bp, 1);
   fn->has_simduid_loops = bp_unpack_value (&bp, 1);
   fn->has_musttail = bp_unpack_value (&bp, 1);
+  fn->has_unroll = bp_unpack_value (&bp, 1);
   fn->assume_function = bp_unpack_value (&bp, 1);
   fn->va_list_fpr_size = bp_unpack_value (&bp, 8);
   fn->va_list_gpr_size = bp_unpack_value (&bp, 8);

diff --git a/gcc/lto-streamer-out.cc b/gcc/lto-streamer-out.cc
index a4b171358d41de345e0951eb46a6f93e79f2f49f..807b935537bef23a7620ceda3c145d48d9a91aea 100644 (file)
--- a/gcc/lto-streamer-out.cc
+++ b/gcc/lto-streamer-out.cc
@@ -2283,6 +2283,7 @@ output_struct_function_base (struct output_block *ob, struct function *fn)
   bp_pack_value (&bp, fn->has_force_vectorize_loops, 1);
   bp_pack_value (&bp, fn->has_simduid_loops, 1);
   bp_pack_value (&bp, fn->has_musttail, 1);
+  bp_pack_value (&bp, fn->has_unroll, 1);
   bp_pack_value (&bp, fn->assume_function, 1);
   bp_pack_value (&bp, fn->va_list_fpr_size, 8);
   bp_pack_value (&bp, fn->va_list_gpr_size, 8);

diff --git a/gcc/testsuite/g++.dg/ext/pragma-unroll-lambda-lto.C b/gcc/testsuite/g++.dg/ext/pragma-unroll-lambda-lto.C
new file mode 100644 (file)
index 0000000..144c4c3
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ext/pragma-unroll-lambda-lto.C
@@ -0,0 +1,32 @@
+// { dg-do link { target c++11 } }
+// { dg-options "-O2 -flto -fdump-rtl-loop2_unroll" }
+
+#include <cstdlib>
+
+template<typename Iter, typename Pred>
+inline Iter
+my_find(Iter first, Iter last, Pred pred)
+{
+#pragma GCC unroll 4
+    while (first != last && !pred(*first))
+        ++first;
+    return first;
+}
+
+__attribute__((noipa))
+short *use_find(short *p)
+{
+    auto pred = [](short x) { return x == 42; };
+    return my_find(p, p + 1024, pred);
+}
+
+int main(void)
+{
+  short a[1024];
+  for (int i = 0; i < 1024; i++)
+    a[i] = rand ();
+
+  return use_find (a) - a;
+}
+
+// { dg-final { scan-ltrans-rtl-dump-times "Unrolled loop 3 times" 1 "loop2_unroll" } }