12 files changed, 32 insertions, 10 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 61b003a..5eb37fa 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2018-01-18  Martin Liska  <mliska@suse.cz>
+
+	* config/i386/i386.c (indirect_thunk_name): Document that also
+	lfence is emitted.
+	(output_indirect_thunk): Document why both instructions
+	(pause and lfence) are generated.
+
 2018-01-18  Richard Biener  <rguenther@suse.de>
 
 	PR tree-optimization/83887
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index cb0f4ed..72d25ae4 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -10826,6 +10826,7 @@ indirect_thunk_name (char name[32], unsigned int regno,
 	call	L2
    L1:
 	pause
+	lfence
 	jmp	L1
    L2:
 	mov	%REG, (%sp)
@@ -10837,6 +10838,7 @@ indirect_thunk_name (char name[32], unsigned int regno,
 	call L2
   L1:
 	pause
+	lfence
 	jmp L1
   L2:
 	lea WORD_SIZE(%sp), %sp
@@ -10864,7 +10866,8 @@ output_indirect_thunk (bool need_bnd_p, unsigned int regno)
 
   ASM_OUTPUT_INTERNAL_LABEL (asm_out_file, indirectlabel1);
 
-  /* Pause + lfence.  */
+  /* AMD and Intel CPUs prefer each a different instruction as loop filler.
+     Usage of both pause + lfence is compromise solution.  */
   fprintf (asm_out_file, "\tpause\n\tlfence\n");
 
   /* Jump.  */
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 73a7b0c..f20400d 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,15 @@
+2018-01-18  Martin Liska  <mliska@suse.cz>
+
+	* gcc.target/i386/indirect-thunk-3.c: Remove duplicate options.
+	* gcc.target/i386/indirect-thunk-4.c: Likewise.
+	* gcc.target/i386/indirect-thunk-6.c: Likewise.
+	* gcc.target/i386/indirect-thunk-bnd-4.c: Likewise.
+	* gcc.target/i386/ret-thunk-10.c: Likewise.
+	* gcc.target/i386/ret-thunk-11.c: Likewise.
+	* gcc.target/i386/ret-thunk-12.c: Likewise.
+	* gcc.target/i386/ret-thunk-15.c: Likewise.
+	* gcc.target/i386/ret-thunk-9.c: Likewise.
+
 2018-01-18  Christophe Lyon  <christophe.lyon@linaro.org>
 
 	* gcc.target/arm/xor-and.c: Fix dg-options and dg-add-options
diff --git a/gcc/testsuite/gcc.target/i386/indirect-thunk-3.c b/gcc/testsuite/gcc.target/i386/indirect-thunk-3.c
index 9e24a38..dab7ac2 100644
--- a/gcc/testsuite/gcc.target/i386/indirect-thunk-3.c
+++ b/gcc/testsuite/gcc.target/i386/indirect-thunk-3.c
@@ -1,5 +1,5 @@
 /* { dg-do compile } */
-/* { dg-options "-O2 -mno-indirect-branch-register -mno-indirect-branch-register -mno-indirect-branch-register -mfunction-return=keep -mindirect-branch=thunk -fno-pic" } */
+/* { dg-options "-O2 -mno-indirect-branch-register -mfunction-return=keep -mindirect-branch=thunk -fno-pic" } */
 
 typedef void (*dispatch_t)(long offset);
 
diff --git a/gcc/testsuite/gcc.target/i386/indirect-thunk-4.c b/gcc/testsuite/gcc.target/i386/indirect-thunk-4.c
index 127b5d9..44cc5f5 100644
--- a/gcc/testsuite/gcc.target/i386/indirect-thunk-4.c
+++ b/gcc/testsuite/gcc.target/i386/indirect-thunk-4.c
@@ -1,5 +1,5 @@
 /* { dg-do compile } */
-/* { dg-options "-O2 -mno-indirect-branch-register -mno-indirect-branch-register -mno-indirect-branch-register -mfunction-return=keep -mindirect-branch=thunk -fno-pic" } */
+/* { dg-options "-O2 -mno-indirect-branch-register -mfunction-return=keep -mindirect-branch=thunk -fno-pic" } */
 
 typedef void (*dispatch_t)(long offset);
 
diff --git a/gcc/testsuite/gcc.target/i386/indirect-thunk-6.c b/gcc/testsuite/gcc.target/i386/indirect-thunk-6.c
index e464928..1490f53 100644
--- a/gcc/testsuite/gcc.target/i386/indirect-thunk-6.c
+++ b/gcc/testsuite/gcc.target/i386/indirect-thunk-6.c
@@ -1,5 +1,5 @@
 /* { dg-do compile { target *-*-linux* } } */
-/* { dg-options "-O2 -mno-indirect-branch-register -mno-indirect-branch-register -mno-indirect-branch-register -mfunction-return=keep -fpic -fno-plt -mindirect-branch=thunk" } */
+/* { dg-options "-O2 -mno-indirect-branch-register -mfunction-return=keep -fpic -fno-plt -mindirect-branch=thunk" } */
 
 extern void bar (void);
 
diff --git a/gcc/testsuite/gcc.target/i386/indirect-thunk-bnd-4.c b/gcc/testsuite/gcc.target/i386/indirect-thunk-bnd-4.c
index 0e19830..a5fc4a2 100644
--- a/gcc/testsuite/gcc.target/i386/indirect-thunk-bnd-4.c
+++ b/gcc/testsuite/gcc.target/i386/indirect-thunk-bnd-4.c
@@ -1,5 +1,5 @@
 /* { dg-do compile { target { *-*-linux* && { ! x32 } } } } */
-/* { dg-options "-O2 -mno-indirect-branch-register -mno-indirect-branch-register -mfunction-return=keep -mindirect-branch=thunk -fcheck-pointer-bounds -mmpx -fpic -fno-plt" } */
+/* { dg-options "-O2 -mno-indirect-branch-register -mfunction-return=keep -mindirect-branch=thunk -fcheck-pointer-bounds -mmpx -fpic -fno-plt" } */
 
 void bar (char *);
 char buf[10];
diff --git a/gcc/testsuite/gcc.target/i386/ret-thunk-10.c b/gcc/testsuite/gcc.target/i386/ret-thunk-10.c
index e6fea84..6de9b8c 100644
--- a/gcc/testsuite/gcc.target/i386/ret-thunk-10.c
+++ b/gcc/testsuite/gcc.target/i386/ret-thunk-10.c
@@ -1,5 +1,5 @@
 /* { dg-do compile } */
-/* { dg-options "-O2 -mno-indirect-branch-register -mno-indirect-branch-register -mfunction-return=thunk-inline -mindirect-branch=thunk -fno-pic" } */
+/* { dg-options "-O2 -mno-indirect-branch-register -mfunction-return=thunk-inline -mindirect-branch=thunk -fno-pic" } */
 
 extern void (*bar) (void);
 
diff --git a/gcc/testsuite/gcc.target/i386/ret-thunk-11.c b/gcc/testsuite/gcc.target/i386/ret-thunk-11.c
index e239ec4..3659803 100644
--- a/gcc/testsuite/gcc.target/i386/ret-thunk-11.c
+++ b/gcc/testsuite/gcc.target/i386/ret-thunk-11.c
@@ -1,5 +1,5 @@
 /* { dg-do compile } */
-/* { dg-options "-O2 -mno-indirect-branch-register -mno-indirect-branch-register -mno-indirect-branch-register -mno-indirect-branch-register -mfunction-return=thunk-extern -mindirect-branch=thunk -fno-pic" } */
+/* { dg-options "-O2 -mno-indirect-branch-register -mfunction-return=thunk-extern -mindirect-branch=thunk -fno-pic" } */
 
 extern void (*bar) (void);
 
diff --git a/gcc/testsuite/gcc.target/i386/ret-thunk-12.c b/gcc/testsuite/gcc.target/i386/ret-thunk-12.c
index fa31813..5fb1a4d 100644
--- a/gcc/testsuite/gcc.target/i386/ret-thunk-12.c
+++ b/gcc/testsuite/gcc.target/i386/ret-thunk-12.c
@@ -1,5 +1,5 @@
 /* { dg-do compile } */
-/* { dg-options "-O2 -mno-indirect-branch-register -mno-indirect-branch-register -mno-indirect-branch-register -mno-indirect-branch-register -mfunction-return=keep -mindirect-branch=thunk -fno-pic" } */
+/* { dg-options "-O2 -mno-indirect-branch-register -mfunction-return=keep -mindirect-branch=thunk -fno-pic" } */
 
 extern void (*bar) (void);
 
diff --git a/gcc/testsuite/gcc.target/i386/ret-thunk-15.c b/gcc/testsuite/gcc.target/i386/ret-thunk-15.c
index 75e45e2..2038644 100644
--- a/gcc/testsuite/gcc.target/i386/ret-thunk-15.c
+++ b/gcc/testsuite/gcc.target/i386/ret-thunk-15.c
@@ -1,5 +1,5 @@
 /* { dg-do compile } */
-/* { dg-options "-O2 -mno-indirect-branch-register -mno-indirect-branch-register -mno-indirect-branch-register -mno-indirect-branch-register -mfunction-return=keep -mindirect-branch=keep -fno-pic" } */
+/* { dg-options "-O2 -mno-indirect-branch-register -mfunction-return=keep -mindirect-branch=keep -fno-pic" } */
 
 extern void (*bar) (void);
 
diff --git a/gcc/testsuite/gcc.target/i386/ret-thunk-9.c b/gcc/testsuite/gcc.target/i386/ret-thunk-9.c
index d1db41c..d34dd4e 100644
--- a/gcc/testsuite/gcc.target/i386/ret-thunk-9.c
+++ b/gcc/testsuite/gcc.target/i386/ret-thunk-9.c
@@ -1,5 +1,5 @@
 /* { dg-do compile } */
-/* { dg-options "-O2 -mno-indirect-branch-register -mno-indirect-branch-register -mfunction-return=thunk -mindirect-branch=thunk -fno-pic" } */
+/* { dg-options "-O2 -mno-indirect-branch-register -mfunction-return=thunk -mindirect-branch=thunk -fno-pic" } */
 
 extern void (*bar) (void);