PR 102281 (-ftrivial-auto-var-init=zero causes ice)

Do not add call to __builtin_clear_padding when a variable is a gimple
register or it might not have padding.

gcc/ChangeLog:

2021-11-01  qing zhao  <qing.zhao@oracle.com>

	* gimplify.c (gimplify_decl_expr): Do not add call to
	__builtin_clear_padding when a variable is a gimple register
	or it might not have padding.
	(gimplify_init_constructor): Likewise.

gcc/testsuite/ChangeLog:

2021-11-01  qing zhao  <qing.zhao@oracle.com>

	* c-c++-common/pr102281.c: New test.
	* gcc.target/i386/auto-init-2.c: Adjust testing case.
	* gcc.target/i386/auto-init-4.c: Likewise.
	* gcc.target/i386/auto-init-6.c: Likewise.
	* gcc.target/aarch64/auto-init-6.c: Likewise.

6 files changed, 47 insertions, 18 deletions

diff --git a/gcc/gimplify.c b/gcc/gimplify.c
index 8bb54fd..c2ab96e 100644
--- a/gcc/gimplify.c
+++ b/gcc/gimplify.c
@@ -1784,8 +1784,8 @@ gimple_add_init_for_auto_var (tree decl,
    that padding is initialized to zero. So, we always initialize paddings
    to zeroes regardless INIT_TYPE.
    To do the padding initialization, we insert a call to
-   __BUILTIN_CLEAR_PADDING (&decl, 0, for_auto_init = true).
-   Note, we add an additional dummy argument for __BUILTIN_CLEAR_PADDING,
+   __builtin_clear_padding (&decl, 0, for_auto_init = true).
+   Note, we add an additional dummy argument for __builtin_clear_padding,
    'for_auto_init' to distinguish whether this call is for automatic
    variable initialization or not.
    */
@@ -1954,8 +1954,14 @@ gimplify_decl_expr (tree *stmt_p, gimple_seq *seq_p)
 	     pattern initialization.
 	     In order to make the paddings as zeroes for pattern init, We
 	     should add a call to __builtin_clear_padding to clear the
-	     paddings to zero in compatiple with CLANG.  */
-	  if (flag_auto_var_init == AUTO_INIT_PATTERN)
+	     paddings to zero in compatiple with CLANG.
+	     We cannot insert this call if the variable is a gimple register
+	     since __builtin_clear_padding will take the address of the
+	     variable.  As a result, if a long double/_Complex long double
+	     variable will spilled into stack later, its padding is 0XFE.  */
+	  if (flag_auto_var_init == AUTO_INIT_PATTERN
+	      && !is_gimple_reg (decl)
+	      && clear_padding_type_may_have_padding_p (TREE_TYPE (decl)))
 	    gimple_add_padding_init_for_auto_var (decl, is_vla, seq_p);
 	}
     }
@@ -5384,12 +5390,19 @@ gimplify_init_constructor (tree *expr_p, gimple_seq *pre_p, gimple_seq *post_p,
 
   /* If the user requests to initialize automatic variables, we
      should initialize paddings inside the variable.  Add a call to
-     __BUILTIN_CLEAR_PADDING (&object, 0, for_auto_init = true) to
+     __builtin_clear_pading (&object, 0, for_auto_init = true) to
      initialize paddings of object always to zero regardless of
      INIT_TYPE.  Note, we will not insert this call if the aggregate
      variable has be completely cleared already or it's initialized
-     with an empty constructor.  */
+     with an empty constructor.  We cannot insert this call if the
+     variable is a gimple register since __builtin_clear_padding will take
+     the address of the variable.  As a result, if a long double/_Complex long
+     double variable will be spilled into stack later, its padding cannot
+     be cleared with __builtin_clear_padding.  We should clear its padding
+     when it is spilled into memory.  */
   if (is_init_expr
+      && !is_gimple_reg (object)
+      && clear_padding_type_may_have_padding_p (type)
       && ((AGGREGATE_TYPE_P (type) && !cleared && !is_empty_ctor)
 	  || !AGGREGATE_TYPE_P (type))
       && is_var_need_auto_init (object))
diff --git a/gcc/testsuite/c-c++-common/pr102281.c b/gcc/testsuite/c-c++-common/pr102281.c
new file mode 100644
index 0000000..a961451
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/pr102281.c
@@ -0,0 +1,17 @@
+/* PR102281  */
+/* { dg-do compile } */
+/* { dg-options "-ftrivial-auto-var-init=zero -Wno-psabi" } */
+long long var1;
+float var2;
+typedef long long V __attribute__((__vector_size__(2 * sizeof(long long))));
+typedef float W __attribute__((__vector_size__(4 * sizeof(float)))); 
+
+V foo (void)
+{
+  return (V) {var1}; 
+}
+
+W bar (void)
+{
+  return (W) {var2};
+}
diff --git a/gcc/testsuite/gcc.target/aarch64/auto-init-6.c b/gcc/testsuite/gcc.target/aarch64/auto-init-6.c
index 27c16b3..0456c66 100644
--- a/gcc/testsuite/gcc.target/aarch64/auto-init-6.c
+++ b/gcc/testsuite/gcc.target/aarch64/auto-init-6.c
@@ -1,6 +1,6 @@
 /* Verify pattern initialization for complex type automatic variables.  */
 /* { dg-do compile } */
-/* { dg-options "-ftrivial-auto-var-init=pattern -fdump-rtl-expand" } */
+/* { dg-options "-ftrivial-auto-var-init=pattern" } */
 
 
 _Complex long double result;
@@ -15,4 +15,4 @@ _Complex long double foo()
   return result;
 }
 
-/* { dg-final { scan-rtl-dump-times "0xfffffffffffffffe\\\]\\\) repeated x16" 3 "expand" } } */
+/* { dg-final { scan-assembler-times "word\t-16843010" 14  } } */
diff --git a/gcc/testsuite/gcc.target/i386/auto-init-2.c b/gcc/testsuite/gcc.target/i386/auto-init-2.c
index e22930a..0c59c62 100644
--- a/gcc/testsuite/gcc.target/i386/auto-init-2.c
+++ b/gcc/testsuite/gcc.target/i386/auto-init-2.c
@@ -29,7 +29,7 @@ void foo()
   return;
 }
 
-/* { dg-final { scan-rtl-dump-times "0xfffffffffffffffe" 2 "expand" } } */
+/* { dg-final { scan-rtl-dump-times "0xfffffffffffffffe" 1 "expand" } } */
 /* { dg-final { scan-rtl-dump-times "0xfffffffffffffefe" 1 "expand" } } */
 /* { dg-final { scan-rtl-dump-times "0xfffffffffefefefe" 2 "expand" { target lp64 } } } */
 /* { dg-final { scan-rtl-dump-times "0xfefefefefefefefe" 3 "expand" { target lp64 } } } */
diff --git a/gcc/testsuite/gcc.target/i386/auto-init-4.c b/gcc/testsuite/gcc.target/i386/auto-init-4.c
index 7b46c74..1803dd4 100644
--- a/gcc/testsuite/gcc.target/i386/auto-init-4.c
+++ b/gcc/testsuite/gcc.target/i386/auto-init-4.c
@@ -1,6 +1,6 @@
 /* Verify pattern initialization for floating point type automatic variables.  */
 /* { dg-do compile } */
-/* { dg-options "-ftrivial-auto-var-init=pattern -fdump-rtl-expand -march=x86-64 -mtune=generic -msse" } */
+/* { dg-options "-ftrivial-auto-var-init=pattern -march=x86-64 -mtune=generic -msse" } */
 
 long double result;
 
@@ -14,8 +14,6 @@ long double foo()
   return result;
 }
 
-/* { dg-final { scan-rtl-dump-times "0xfffffffffefefefe" 1 "expand" { target { ! ia32 } } } } */
-/* { dg-final { scan-rtl-dump-times "\\\[0xfefefefefefefefe\\\]" 1 "expand" { target { ! ia32 } } } } */
-/* { dg-final { scan-rtl-dump-times "0xfffffffffffffffe\\\]\\\) repeated x16" 1 "expand" { target { ! ia32 } } } } */
-/* { dg-final { scan-rtl-dump-times "0xfffffffffefefefe" 2 "expand" { target ia32 } } } */
-/* { dg-final { scan-rtl-dump-times "\\\[0xfefefefefefefefe\\\]" 2 "expand" { target ia32 } } } */
+
+/* { dg-final { scan-assembler-times "long\t-16843010" 5  { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "long\t-16843010" 3  { target { ia32 } } } } */
diff --git a/gcc/testsuite/gcc.target/i386/auto-init-6.c b/gcc/testsuite/gcc.target/i386/auto-init-6.c
index f75081e..339f8bc 100644
--- a/gcc/testsuite/gcc.target/i386/auto-init-6.c
+++ b/gcc/testsuite/gcc.target/i386/auto-init-6.c
@@ -1,6 +1,6 @@
 /* Verify pattern initialization for complex type automatic variables.  */
 /* { dg-do compile } */
-/* { dg-options "-ftrivial-auto-var-init=pattern -fdump-rtl-expand -march=x86-64 -mtune=generic -msse" } */
+/* { dg-options "-ftrivial-auto-var-init=pattern -march=x86-64 -mtune=generic -msse" } */
 
 
 _Complex long double result;
@@ -15,5 +15,6 @@ _Complex long double foo()
   return result;
 }
 
-/* { dg-final { scan-rtl-dump-times "\\\[0xfefefefefefefefe\\\]" 1 "expand" } } */
-/* { dg-final { scan-rtl-dump-times "0xfffffffffffffffe\\\]\\\) repeated x16" 2 "expand" } } */
+/* { dg-final { scan-assembler-times "long\t-16843010" 10  { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "long\t-16843010" 6  { target { ia32 } } } } */
+