From: Pan Li <pan2.li@intel.com>
Date: Tue, 2 Jul 2024 00:57:50 +0000 (+0800)
Subject: Match: Allow more types truncation for .SAT_TRUNC
X-Git-Tag: basepoints/gcc-16~7733
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=44c767c06b6882d05fe56f4a3e03195101402fb0;p=thirdparty%2Fgcc.git

Match: Allow more types truncation for .SAT_TRUNC

The .SAT_TRUNC has the input and output types,  aka cvt from
itype to otype and the sizeof (otype) < sizeof (itype).  The
previous patch only allows the sizeof (otype) == sizeof (itype) / 2.
But actually we have 1/4 and 1/8 truncation.

This patch would like to support more types trunction when
sizeof (otype) < sizeof (itype).  The below truncation will be
covered.

* uint64_t => uint8_t
* uint64_t => uint16_t
* uint64_t => uint32_t
* uint32_t => uint8_t
* uint32_t => uint16_t
* uint16_t => uint8_t

The below test suites are passed for this patch:
1. The rv64gcv fully regression tests.
2. The rv64gcv build with glibc.
3. The x86 bootstrap tests.
4. The x86 fully regression tests.

gcc/ChangeLog:

	* match.pd: Allow any otype is less than itype truncation.

Signed-off-by: Pan Li <pan2.li@intel.com>
---

diff --git a/gcc/match.pd b/gcc/match.pd
index a2e205b3207..4edfa2ae2c9 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -3239,16 +3239,16 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
 (match (unsigned_integer_sat_trunc @0)
  (bit_ior:c (negate (convert (gt @0 INTEGER_CST@1)))
    (convert @0))
- (with {
+ (if (INTEGRAL_TYPE_P (type) && TYPE_UNSIGNED (type)
+      && TYPE_UNSIGNED (TREE_TYPE (@0)))
+ (with
+  {
    unsigned itype_precision = TYPE_PRECISION (TREE_TYPE (@0));
    unsigned otype_precision = TYPE_PRECISION (type);
-   wide_int trunc_max = wi::mask (itype_precision / 2, false, itype_precision);
+   wide_int trunc_max = wi::mask (otype_precision, false, itype_precision);
    wide_int int_cst = wi::to_wide (@1, itype_precision);
   }
-  (if (INTEGRAL_TYPE_P (type) && TYPE_UNSIGNED (type)
-       && TYPE_UNSIGNED (TREE_TYPE (@0))
-       && otype_precision < itype_precision
-       && wi::eq_p (trunc_max, int_cst)))))
+  (if (otype_precision < itype_precision && wi::eq_p (trunc_max, int_cst))))))
 
 /* x >  y  &&  x != XXX_MIN  -->  x > y
    x >  y  &&  x == XXX_MIN  -->  false . */