From 72982851d70dfbc547d83ed2bb45356b9ebe3ff0 Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Tue, 23 Mar 2021 20:04:58 -0700
Subject: [PATCH] x86: Skip ISA check for always_inline in system headers

For always_inline in system headers, we don't know if caller's ISAs are
compatible with callee's ISAs until much later.  Skip ISA check for
always_inline in system headers if caller has target attribute.

gcc/

	PR target/98209
	PR target/99744
	* config/i386/i386.c (ix86_can_inline_p): Don't check ISA for
	always_inline in system headers.

gcc/testsuite/

	PR target/98209
	PR target/99744
	* gcc.target/i386/pr98209.c: New test.
	* gcc.target/i386/pr99744-1.c: Likewise.
	* gcc.target/i386/pr99744-2.c: Likewise.
---
 gcc/config/i386/i386.c                    | 24 +++++++++++++++--------
 gcc/testsuite/gcc.target/i386/pr98209.c   | 13 ++++++++++++
 gcc/testsuite/gcc.target/i386/pr99744-1.c | 16 +++++++++++++++
 gcc/testsuite/gcc.target/i386/pr99744-2.c | 13 ++++++++++++
 4 files changed, 58 insertions(+), 8 deletions(-)
 create mode 100644 gcc/testsuite/gcc.target/i386/pr98209.c
 create mode 100644 gcc/testsuite/gcc.target/i386/pr99744-1.c
 create mode 100644 gcc/testsuite/gcc.target/i386/pr99744-2.c

diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 7c41302c75b..1b4567e34ba 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -578,21 +578,29 @@ ix86_can_inline_p (tree caller, tree callee)
        && lookup_attribute ("always_inline",
 			    DECL_ATTRIBUTES (callee)));
 
+  /* NB: Skip ISA check for always_inline in system headers if caller
+     has target attribute.  */
+  bool skip_isa_check = (always_inline
+			 && caller_tree != target_option_default_node
+			 && DECL_IN_SYSTEM_HEADER (callee));
+
   cgraph_node *callee_node = cgraph_node::get (callee);
   /* Callee's isa options should be a subset of the caller's, i.e. a SSE4
      function can inline a SSE2 function but a SSE2 function can't inline
      a SSE4 function.  */
-  if (((caller_opts->x_ix86_isa_flags & callee_opts->x_ix86_isa_flags)
-       != callee_opts->x_ix86_isa_flags)
-      || ((caller_opts->x_ix86_isa_flags2 & callee_opts->x_ix86_isa_flags2)
-	  != callee_opts->x_ix86_isa_flags2))
+  if (!skip_isa_check
+      && (((caller_opts->x_ix86_isa_flags & callee_opts->x_ix86_isa_flags)
+	   != callee_opts->x_ix86_isa_flags)
+	  || ((caller_opts->x_ix86_isa_flags2 & callee_opts->x_ix86_isa_flags2)
+	      != callee_opts->x_ix86_isa_flags2)))
     ret = false;
 
   /* See if we have the same non-isa options.  */
-  else if ((!always_inline
-	    && caller_opts->x_target_flags != callee_opts->x_target_flags)
-	   || (caller_opts->x_target_flags & ~always_inline_safe_mask)
-	       != (callee_opts->x_target_flags & ~always_inline_safe_mask))
+  else if (!skip_isa_check
+	   && ((!always_inline
+		&& caller_opts->x_target_flags != callee_opts->x_target_flags)
+	       || ((caller_opts->x_target_flags & ~always_inline_safe_mask)
+		   != (callee_opts->x_target_flags & ~always_inline_safe_mask))))
     ret = false;
 
   /* See if arch, tune, etc. are the same.  */
diff --git a/gcc/testsuite/gcc.target/i386/pr98209.c b/gcc/testsuite/gcc.target/i386/pr98209.c
new file mode 100644
index 00000000000..4566d4c7fc3
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr98209.c
@@ -0,0 +1,13 @@
+/* { dg-do run { target *-*-linux* } } */
+/* { dg-options "-O2 -D_FORTIFY_SOURCE=2" } */
+
+#include <stdio.h>
+
+extern int main(int argc, char** argv)
+  __attribute__ ((__target__ ("no-sse,no-mmx")));
+
+int main(int argc, char** argv)
+{
+  printf ("hello!\n");
+  return 0;
+}
diff --git a/gcc/testsuite/gcc.target/i386/pr99744-1.c b/gcc/testsuite/gcc.target/i386/pr99744-1.c
new file mode 100644
index 00000000000..92535923a56
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr99744-1.c
@@ -0,0 +1,16 @@
+/* { dg-do compile } */
+/* { dg-options "-O0" } */
+
+#include <x86intrin.h>
+
+extern unsigned long long int curr_deadline;
+extern void bar (void);
+
+__attribute__ ((target("general-regs-only")))
+void
+foo (void)
+{
+  if (__rdtsc () < curr_deadline)
+    return; 
+  bar ();
+}
diff --git a/gcc/testsuite/gcc.target/i386/pr99744-2.c b/gcc/testsuite/gcc.target/i386/pr99744-2.c
new file mode 100644
index 00000000000..4bb2a6bb6dc
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr99744-2.c
@@ -0,0 +1,13 @@
+/* { dg-do compile { target { ! ia32 } } } */
+/* { dg-options "-O2" } */
+
+#include <x86intrin.h>
+
+extern __m128i x, y;
+
+__attribute__ ((target("general-regs-only")))
+void
+foo (void)
+{
+  x = _mm_move_epi64 (y); /* { dg-error "SSE register return with SSE disabled" } */
+}