PR116080: Fix test suite checks for musttail

This is a new attempt to fix PR116080. The previous try was reverted
because it just broke a bunch of tests, hiding the problem.

- musttail behaves differently than tailcall at -O0. Some of the test
run at -O0, so add separate effective target tests for musttail.
- New effective target tests need to use unique file names
to make dejagnu caching work
- Change the tests to use new targets
- Add a external_musttail test to check for target's ability
to do tail calls between translation units. This covers some powerpc
ABIs.

gcc/testsuite/ChangeLog:

	PR testsuite/116080
	* c-c++-common/musttail1.c: Use musttail target.
	* c-c++-common/musttail12.c: Use struct_musttail target.
	* c-c++-common/musttail2.c: Use musttail target.
	* c-c++-common/musttail3.c: Likewise.
	* c-c++-common/musttail4.c: Likewise.
	* c-c++-common/musttail7.c: Likewise.
	* c-c++-common/musttail8.c: Likewise.
	* g++.dg/musttail10.C: Likewise. Replace powerpc checks with
	external_musttail.
	* g++.dg/musttail11.C: Use musttail target.
	* g++.dg/musttail6.C: Use musttail target. Replace powerpc
	checks with external_musttail.
	* g++.dg/musttail9.C: Use musttail target.
	* lib/target-supports.exp: Add musttail, struct_musttail,
	external_musttail targets. Remove optimization for musttail.
	Use unique file names for musttail.

12 files changed, 38 insertions, 20 deletions

diff --git a/gcc/testsuite/c-c++-common/musttail1.c b/gcc/testsuite/c-c++-common/musttail1.c
index 74efcc2..5154967 100644
--- a/gcc/testsuite/c-c++-common/musttail1.c
+++ b/gcc/testsuite/c-c++-common/musttail1.c
@@ -1,4 +1,4 @@
-/* { dg-do compile { target { tail_call && { c || c++11 } } } } */
+/* { dg-do compile { target { musttail && { c || c++11 } } } } */
 /* { dg-additional-options "-fdelayed-branch" { target sparc*-*-* } } */
 
 int __attribute__((noinline,noclone,noipa))
diff --git a/gcc/testsuite/c-c++-common/musttail12.c b/gcc/testsuite/c-c++-common/musttail12.c
index 4140bcd..475afc5 100644
--- a/gcc/testsuite/c-c++-common/musttail12.c
+++ b/gcc/testsuite/c-c++-common/musttail12.c
@@ -1,4 +1,4 @@
-/* { dg-do compile { target { struct_tail_call && { c || c++11 } } } } */
+/* { dg-do compile { target { struct_musttail && { c || c++11 } } } } */
 /* { dg-additional-options "-fdelayed-branch" { target sparc*-*-* } } */
 
 struct str
diff --git a/gcc/testsuite/c-c++-common/musttail2.c b/gcc/testsuite/c-c++-common/musttail2.c
index 86f2c3d..1970c4e 100644
--- a/gcc/testsuite/c-c++-common/musttail2.c
+++ b/gcc/testsuite/c-c++-common/musttail2.c
@@ -1,4 +1,4 @@
-/* { dg-do compile { target { tail_call && { c || c++11 } } } } */
+/* { dg-do compile { target { musttail && { c || c++11 } } } } */
 
 struct box { char field[256]; int i; };
 
diff --git a/gcc/testsuite/c-c++-common/musttail3.c b/gcc/testsuite/c-c++-common/musttail3.c
index ea9589c..7499fd6 100644
--- a/gcc/testsuite/c-c++-common/musttail3.c
+++ b/gcc/testsuite/c-c++-common/musttail3.c
@@ -1,4 +1,4 @@
-/* { dg-do compile { target { tail_call && { c || c++11 } } } } */
+/* { dg-do compile { target { struct_musttail && { c || c++11 } } } } */
 
 extern int foo2 (int x, ...);
 
diff --git a/gcc/testsuite/c-c++-common/musttail4.c b/gcc/testsuite/c-c++-common/musttail4.c
index 23f4b5e..bd6effa4 100644
--- a/gcc/testsuite/c-c++-common/musttail4.c
+++ b/gcc/testsuite/c-c++-common/musttail4.c
@@ -1,4 +1,4 @@
-/* { dg-do compile { target { tail_call && { c || c++11 } } } } */
+/* { dg-do compile { target { musttail && { c || c++11 } } } } */
 
 struct box { char field[64]; int i; };
 
diff --git a/gcc/testsuite/c-c++-common/musttail7.c b/gcc/testsuite/c-c++-common/musttail7.c
index c753a3f..d17cb71 100644
--- a/gcc/testsuite/c-c++-common/musttail7.c
+++ b/gcc/testsuite/c-c++-common/musttail7.c
@@ -1,4 +1,4 @@
-/* { dg-do compile { target { tail_call && { c || c++11 } } } } */
+/* { dg-do compile { target { musttail && { c || c++11 } } } } */
 /* { dg-additional-options "-fdelayed-branch" { target sparc*-*-* } } */
 
 void __attribute__((noipa)) f() {}
diff --git a/gcc/testsuite/c-c++-common/musttail8.c b/gcc/testsuite/c-c++-common/musttail8.c
index 9fa10e0..50ca1ac 100644
--- a/gcc/testsuite/c-c++-common/musttail8.c
+++ b/gcc/testsuite/c-c++-common/musttail8.c
@@ -1,4 +1,4 @@
-/* { dg-do compile { target { tail_call && { c || c++11 } } } } */
+/* { dg-do compile { target { musttail && { c || c++11 } } } } */
 
 float f1(void);
 
diff --git a/gcc/testsuite/g++.dg/musttail10.C b/gcc/testsuite/g++.dg/musttail10.C
index ff7fcc7..a43d8a6 100644
--- a/gcc/testsuite/g++.dg/musttail10.C
+++ b/gcc/testsuite/g++.dg/musttail10.C
@@ -1,4 +1,4 @@
-/* { dg-do compile { target { tail_call } } } */
+/* { dg-do compile { target { musttail } } } */
 /* { dg-options "-std=gnu++11" } */
 /* { dg-additional-options "-fdelayed-branch" { target sparc*-*-* } } */
 
@@ -8,11 +8,11 @@ double g() { [[gnu::musttail]] return f<int>(); } /* { dg-error "cannot tail-cal
 
 template <class T>
 __attribute__((noinline, noclone, noipa))
-T g1() { [[gnu::musttail]] return f<T>(); } /* { dg-error "target is not able" "" { target powerpc*-*-* } } */
+T g1() { [[gnu::musttail]] return f<T>(); } /* { dg-error "target is not able" "" { target { ! external_musttail } } } */
 
 template <class T>
 __attribute__((noinline, noclone, noipa))
-T g2() { [[gnu::musttail]] return f<T>(); }
+T g2() { [[gnu::musttail]] return f<T>(); } /* { dg-error "target is not able" "" { target { ! external_musttail } } } */
 
 template <class T>
 __attribute__((noinline, noclone, noipa))
diff --git a/gcc/testsuite/g++.dg/musttail11.C b/gcc/testsuite/g++.dg/musttail11.C
index 1779e32..dca8724 100644
--- a/gcc/testsuite/g++.dg/musttail11.C
+++ b/gcc/testsuite/g++.dg/musttail11.C
@@ -1,4 +1,4 @@
-/* { dg-do compile { target { tail_call } } } */
+/* { dg-do compile { target { musttail } } } */
 /* { dg-options "-std=gnu++11" } */
 /* { dg-additional-options "-fdelayed-branch" { target sparc*-*-* } } */
 
diff --git a/gcc/testsuite/g++.dg/musttail6.C b/gcc/testsuite/g++.dg/musttail6.C
index 5c6f694..5dcf302 100644
--- a/gcc/testsuite/g++.dg/musttail6.C
+++ b/gcc/testsuite/g++.dg/musttail6.C
@@ -1,6 +1,6 @@
-/* { dg-do compile { target { struct_tail_call } } } */
+/* { dg-do compile { target { struct_musttail } } } */
+/* { dg-require-effective-target external_musttail } */
 /* A lot of architectures will not build this due to PR115606 and PR115607 */
-/* { dg-skip-if "powerpc does not support sibcall to templates" { powerpc*-*-* } } */
 /* { dg-options "-std=gnu++11" } */
 /* { dg-additional-options "-fdelayed-branch" { target sparc*-*-* } } */
 
diff --git a/gcc/testsuite/g++.dg/musttail9.C b/gcc/testsuite/g++.dg/musttail9.C
index fb0262e..85937dc 100644
--- a/gcc/testsuite/g++.dg/musttail9.C
+++ b/gcc/testsuite/g++.dg/musttail9.C
@@ -1,4 +1,4 @@
-/* { dg-do compile { target { tail_call } } } */
+/* { dg-do compile { target { musttail } } } */
 /* { dg-options "-std=gnu++11" } */
 /* { dg-additional-options "-fdelayed-branch" { target sparc*-*-* } } */
 
diff --git a/gcc/testsuite/lib/target-supports.exp b/gcc/testsuite/lib/target-supports.exp
index d3569c8..d537d30 100644
--- a/gcc/testsuite/lib/target-supports.exp
+++ b/gcc/testsuite/lib/target-supports.exp
@@ -12808,16 +12808,34 @@ proc check_effective_target_tail_call { } {
     } {-O2 -fdump-rtl-expand-all}] ;# The "SIBCALL" note requires a detailed dump.
 }
 
-# Return 1 if the target can perform tail-call optimizations for structures
+# Return 1 if the target can perform musttail optimizations of the
+# most trivial type. This is separate from tail_call because musttail
+# is supported at -O0.
+proc check_effective_target_musttail { } {
+    return [check_no_messages_and_pattern musttail ",SIBCALL" rtl-expand {
+	__attribute__((__noipa__)) void foo (void) { }
+	__attribute__((__noipa__)) void bar (void) { [[gnu::musttail]] return foo(); }
+    } {-fdump-rtl-expand-all}] ;# The "SIBCALL" note requires a detailed dump.
+}
+
+# Return 1 if the target can perform musttail for externals
+proc check_effective_target_external_musttail { } {
+    return [check_no_messages_and_pattern external_musttail ",SIBCALL" rtl-expand {
+	extern __attribute__((__noipa__)) void foo (void);
+	__attribute__((__noipa__)) void bar (void) { [[gnu::musttail]] return foo(); }
+    } {-fdump-rtl-expand-all}] ;# The "SIBCALL" note requires a detailed dump.
+}
+
+# Return 1 if the target can perform musttail optimizations for structures
 # checking with C++ because the C++ compiler has less tail call ability
 # due to PR115606 on some targets
-proc check_effective_target_struct_tail_call { } {
-    return [check_no_messages_and_pattern tail_call ",SIBCALL" rtl-expand {
+proc check_effective_target_struct_musttail { } {
+    return [check_no_messages_and_pattern struct_musttail ",SIBCALL" rtl-expand {
 	// C++
 	struct foo { int a, b; };
-	__attribute__((__noipa__)) struct foo foo (void) { return {}; }
-	__attribute__((__noipa__)) struct foo bar (void) { return foo(); }
-    } {-O2 -fdump-rtl-expand-all}] ;# The "SIBCALL" note requires a detailed dump.
+	extern __attribute__((__noipa__)) struct foo foo (void);
+	__attribute__((__noipa__)) struct foo bar (void) { [[gnu::musttail]] return foo(); }
+    } {-fdump-rtl-expand-all}] ;# The "SIBCALL" note requires a detailed dump.
 }
 
 # Return 1 if the target's calling sequence or its ABI