From: Qing Zhao <qing.zhao@oracle.com>
Date: Wed, 10 Nov 2021 17:59:31 +0000 (+0000)
Subject: Apply pattern initialization only when have_insn_for return true.
X-Git-Tag: basepoints/gcc-13~3180
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=1c04af34c9c66d8ed9f6c12c97dd064238ddfa20;p=thirdparty%2Fgcc.git

Apply pattern initialization only when have_insn_for return true.

For -ftrivial-auto-var-init=pattern, initialize the variable with patterns only
when have_insn_for (SET, mode) return true.  Otherwise initialize it with zeros.
with this change, _Complex long double on X86 is initialized to zero for
pattern initialization.

gcc/ChangeLog:

2021-11-10  qing zhao  <qing.zhao@oracle.com>

	* internal-fn.c (expand_DEFERRED_INIT): Apply pattern initialization
	only when have_insn_for return true for the mode. Fix a memory leak.

gcc/testsuite/ChangeLog:

2021-11-10  qing zhao  <qing.zhao@oracle.com>

	* gcc.target/i386/auto-init-6.c: _Complex long double is initialized
	to zero now with -ftrivial-auto-var-init=pattern.
---

diff --git a/gcc/internal-fn.c b/gcc/internal-fn.c
index 0cba95411a63..e8fd16b9c21f 100644
--- a/gcc/internal-fn.c
+++ b/gcc/internal-fn.c
@@ -3059,10 +3059,10 @@ expand_DEFERRED_INIT (internal_fn, gcall *stmt)
       mark_addressable (lhs);
       tree var_addr = build_fold_addr_expr (lhs);
 
-      tree value = (init_type == AUTO_INIT_PATTERN) ?
-		    build_int_cst (integer_type_node,
-				   INIT_PATTERN_VALUE) :
-		    integer_zero_node;
+      tree value = (init_type == AUTO_INIT_PATTERN)
+		    ? build_int_cst (integer_type_node,
+				     INIT_PATTERN_VALUE)
+		    : integer_zero_node;
       tree m_call = build_call_expr (builtin_decl_implicit (BUILT_IN_MEMSET),
 				     3, var_addr, value, var_size);
       /* Expand this memset call.  */
@@ -3073,15 +3073,17 @@ expand_DEFERRED_INIT (internal_fn, gcall *stmt)
       /* If this variable is in a register use expand_assignment.
 	 For boolean scalars force zero-init.  */
       tree init;
+      scalar_int_mode var_mode;
       if (TREE_CODE (TREE_TYPE (lhs)) != BOOLEAN_TYPE
 	  && tree_fits_uhwi_p (var_size)
 	  && (init_type == AUTO_INIT_PATTERN
 	      || !is_gimple_reg_type (var_type))
 	  && int_mode_for_size (tree_to_uhwi (var_size) * BITS_PER_UNIT,
-				0).exists ())
+				0).exists (&var_mode)
+	  && have_insn_for (SET, var_mode))
 	{
 	  unsigned HOST_WIDE_INT total_bytes = tree_to_uhwi (var_size);
-	  unsigned char *buf = (unsigned char *) xmalloc (total_bytes);
+	  unsigned char *buf = XALLOCAVEC (unsigned char, total_bytes);
 	  memset (buf, (init_type == AUTO_INIT_PATTERN
 			? INIT_PATTERN_VALUE : 0), total_bytes);
 	  tree itype = build_nonstandard_integer_type
diff --git a/gcc/testsuite/gcc.target/i386/auto-init-6.c b/gcc/testsuite/gcc.target/i386/auto-init-6.c
index 339f8bc29660..e53385f0eb74 100644
--- a/gcc/testsuite/gcc.target/i386/auto-init-6.c
+++ b/gcc/testsuite/gcc.target/i386/auto-init-6.c
@@ -1,4 +1,6 @@
 /* Verify pattern initialization for complex type automatic variables.  */
+/* Note, _Complex long double is initialized to zeroes due to the current
+   implemenation limitation.  */
 /* { dg-do compile } */
 /* { dg-options "-ftrivial-auto-var-init=pattern -march=x86-64 -mtune=generic -msse" } */
 
@@ -15,6 +17,6 @@ _Complex long double foo()
   return result;
 }
 
-/* { dg-final { scan-assembler-times "long\t-16843010" 10  { target { ! ia32 } } } } */
-/* { dg-final { scan-assembler-times "long\t-16843010" 6  { target { ia32 } } } } */
+/* { dg-final { scan-assembler-times "long\t0" 8  { target { ! ia32 } } } } */
+/* { dg-final { scan-assembler-times "long\t-16843010" 6  } } */