[gcc r13-3507] i386: add reset_cpu_feature

[Martin Liska <marxin@gcc.gnu.org>]

https://gcc.gnu.org/g:d80b7744c6ae6f6d8ca1f56982a50d1888b8279f

commit r13-3507-gd80b7744c6ae6f6d8ca1f56982a50d1888b8279f
Author: Martin Liska <mliska@suse.cz>
Date:   Tue Oct 25 06:28:44 2022 +0200

    i386: add reset_cpu_feature
    
    gcc/ChangeLog:
    
            * common/config/i386/cpuinfo.h (has_cpu_feature): Add comment.
            (reset_cpu_feature): New.
            (get_zhaoxin_cpu): Use reset_cpu_feature.

Diff:
---
 gcc/common/config/i386/cpuinfo.h | 38 +++++++++++++++++++++++++++++++++-----
 1 file changed, 33 insertions(+), 5 deletions(-)

diff --git a/gcc/common/config/i386/cpuinfo.h b/gcc/common/config/i386/cpuinfo.h
index d45451c5704..19ea7132fd5 100644
--- a/gcc/common/config/i386/cpuinfo.h
+++ b/gcc/common/config/i386/cpuinfo.h
@@ -76,6 +76,8 @@ has_cpu_feature (struct __processor_model *cpu_model,
     }
 }
 
+/* Save FEATURE to either CPU_MODEL or CPU_FEATURES2.  */
+
 static inline void
 set_cpu_feature (struct __processor_model *cpu_model,
 		 unsigned int *cpu_features2,
@@ -100,6 +102,32 @@ set_cpu_feature (struct __processor_model *cpu_model,
     }
 }
 
+/* Drop FEATURE from either CPU_MODEL or CPU_FEATURES2.  */
+
+static inline void
+reset_cpu_feature (struct __processor_model *cpu_model,
+		   unsigned int *cpu_features2,
+		   enum processor_features feature)
+{
+  unsigned index, offset;
+  unsigned f = feature;
+
+  if (f < 32)
+    {
+      /* The first 32 features.  */
+      cpu_model->__cpu_features[0] &= ~(1U << f);
+    }
+  else
+    {
+      /* The rest of features.  cpu_features2[i] contains features from
+	 (32 + i * 32) to (31 + 32 + i * 32), inclusively.  */
+      f -= 32;
+      index = f / 32;
+      offset = f % 32;
+      cpu_features2[index] &= ~(1U << offset);
+    }
+}
+
 /* Get the specific type of AMD CPU and return AMD CPU name.  Return
    NULL for unknown AMD CPU.  */
 
@@ -565,11 +593,11 @@ get_zhaoxin_cpu (struct __processor_model *cpu_model,
       cpu_model->__cpu_type = ZHAOXIN_FAM7H;
       if (model == 0x3b)
 	{
-	cpu = "lujiazui";
-	CHECK___builtin_cpu_is ("lujiazui");
-	cpu_model->__cpu_features[0] &= ~(1U <<(FEATURE_AVX & 31));
-	cpu_features2[0] &= ~(1U <<((FEATURE_F16C - 32) & 31));
-	cpu_model->__cpu_subtype = ZHAOXIN_FAM7H_LUJIAZUI;
+	  cpu = "lujiazui";
+	  CHECK___builtin_cpu_is ("lujiazui");
+	  reset_cpu_feature (cpu_model, cpu_features2, FEATURE_AVX);
+	  reset_cpu_feature (cpu_model, cpu_features2, FEATURE_F16C);
+	  cpu_model->__cpu_subtype = ZHAOXIN_FAM7H_LUJIAZUI;
 	}
       break;
     default: