From: Jakub Jelinek <jakub@redhat.com>
Date: Thu, 22 Oct 2020 07:34:28 +0000 (+0200)
Subject: phiopt: Optimize x ? __builtin_clz (x) : 32 in GIMPLE fallout [PR97503]
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=ef2d3ec325b1b720df5da20784eba46249af2294;p=gcc.git

phiopt: Optimize x ? __builtin_clz (x) : 32 in GIMPLE fallout [PR97503]

> this broke sparc-sun-solaris2.11 bootstrap
>
> /vol/gcc/src/hg/master/local/gcc/tree-ssa-phiopt.c: In function 'bool cond_removal_in_popcount_clz_ctz_pattern(basic_block, basic_block, edge, edge, gimple*, tree, tree)':
> /vol/gcc/src/hg/master/local/gcc/tree-ssa-phiopt.c:1858:27: error: variable 'mode' set but not used [-Werror=unused-but-set-variable]
>  1858 |           scalar_int_mode mode = SCALAR_INT_TYPE_MODE (TREE_TYPE (arg));
>       |                           ^~~~
>
>
> and doubtlessly several other targets that use the defaults.h definition of
>
> #define CTZ_DEFINED_VALUE_AT_ZERO(MODE, VALUE)  0

Ugh, seems many of those macros do not evaluate the first argument.
This got broken by the change to direct_internal_fn_supported_p, previously
it used mode also in the optab test.

2020-10-22  Jakub Jelinek  <jakub@redhat.com>

	* tree-ssa-phiopt.c (cond_removal_in_popcount_clz_ctz_pattern):
	For CLZ and CTZ tests, use type temporary instead of mode.
---

diff --git a/gcc/tree-ssa-phiopt.c b/gcc/tree-ssa-phiopt.c
index c7e84dac512..aa6bb88848b 100644
--- a/gcc/tree-ssa-phiopt.c
+++ b/gcc/tree-ssa-phiopt.c
@@ -1842,10 +1842,10 @@ cond_removal_in_popcount_clz_ctz_pattern (basic_block cond_bb,
     CASE_CFN_CLZ:
       if (INTEGRAL_TYPE_P (TREE_TYPE (arg)))
 	{
-	  scalar_int_mode mode = SCALAR_INT_TYPE_MODE (TREE_TYPE (arg));
-	  if (direct_internal_fn_supported_p (IFN_CLZ, TREE_TYPE (arg),
-					      OPTIMIZE_FOR_BOTH)
-	      && CLZ_DEFINED_VALUE_AT_ZERO (mode, val) == 2)
+	  tree type = TREE_TYPE (arg);
+	  if (direct_internal_fn_supported_p (IFN_CLZ, type, OPTIMIZE_FOR_BOTH)
+	      && CLZ_DEFINED_VALUE_AT_ZERO (SCALAR_INT_TYPE_MODE (type),
+					    val) == 2)
 	    {
 	      ifn = IFN_CLZ;
 	      break;
@@ -1855,10 +1855,10 @@ cond_removal_in_popcount_clz_ctz_pattern (basic_block cond_bb,
     CASE_CFN_CTZ:
       if (INTEGRAL_TYPE_P (TREE_TYPE (arg)))
 	{
-	  scalar_int_mode mode = SCALAR_INT_TYPE_MODE (TREE_TYPE (arg));
-	  if (direct_internal_fn_supported_p (IFN_CTZ, TREE_TYPE (arg),
-					      OPTIMIZE_FOR_BOTH)
-	      && CTZ_DEFINED_VALUE_AT_ZERO (mode, val) == 2)
+	  tree type = TREE_TYPE (arg);
+	  if (direct_internal_fn_supported_p (IFN_CTZ, type, OPTIMIZE_FOR_BOTH)
+	      && CTZ_DEFINED_VALUE_AT_ZERO (SCALAR_INT_TYPE_MODE (type),
+					    val) == 2)
 	    {
 	      ifn = IFN_CTZ;
 	      break;