[X86] Remove TuningPOPCNTFalseDeps from AlderLake

This false dependency issue was fixed in CannonLake looking at the data
from uops.info. This is confirmed not to be an issue based on
benchmarking data in #153983. Setting this can potentially lead to extra
xor instructions whihc could consume extra frontend/renaming resources.

None of the other CPUs that have had this fixed have the tuning flag.

Fixes #153983.

Author: boomanaiden154

llvm/lib/Target/X86/X86.td

@@ -1291,7 +1291,9 @@ def ProcessorFeatures {
   list<SubtargetFeature> ADLAdditionalTuning = [TuningPERMFalseDeps,
                                                 TuningPreferMovmskOverVTest,
                                                 TuningFastImmVectorShift];
-  list<SubtargetFeature> ADLTuning = !listconcat(SKLTuning, ADLAdditionalTuning);
+  list<SubtargetFeature> ADLRemoveTuning = [TuningPOPCNTFalseDeps];
+  list<SubtargetFeature> ADLTuning =
+      !listremove(!listconcat(SKLTuning, ADLAdditionalTuning), ADLRemoveTuning);
   list<SubtargetFeature> ADLFeatures =
     !listconcat(TRMFeatures, ADLAdditionalFeatures);
 

llvm/test/CodeGen/X86/bitcnt-false-dep.ll

@@ -1,6 +1,7 @@
 ; RUN: llc < %s -mtriple=x86_64-unknown-linux-gnu -mcpu=haswell | FileCheck %s --check-prefix=HSW
 ; RUN: llc < %s -mtriple=x86_64-unknown-linux-gnu -mcpu=skylake | FileCheck %s --check-prefix=SKL
 ; RUN: llc < %s -mtriple=x86_64-unknown-linux-gnu -mcpu=skx | FileCheck %s --check-prefix=SKL
+; RUN: llc < %s -mtriple=x86_64-unknown-linux-gnu -mcpu=alderlake | FileCheck %s --check-prefix=ADL
 ; RUN: llc < %s -mtriple=x86_64-unknown-linux-gnu -mcpu=silvermont -mattr=+lzcnt,+bmi | FileCheck %s --check-prefix=SKL
 ; RUN: llc < %s -mtriple=x86_64-unknown-linux-gnu -mcpu=goldmont -mattr=+lzcnt,+bmi | FileCheck %s --check-prefix=SKL
 
@@ -37,6 +38,10 @@ ret:
 ;SKL-LABEL:@loopdep_popcnt32
 ;SKL: xorl [[GPR0:%e[a-d]x]], [[GPR0]]
 ;SKL-NEXT: popcntl {{.*}}, [[GPR0]]
+
+;ADL-LABEL:@loopdep_popcnt32
+;ADL-NOT: xor
+;ADL: popcntl
 }
 
 define i64 @loopdep_popcnt64(ptr nocapture %x, ptr nocapture %y) nounwind {
@@ -63,6 +68,10 @@ ret:
 ;SKL-LABEL:@loopdep_popcnt64
 ;SKL: xorl %e[[GPR0:[a-d]x]], %e[[GPR0]]
 ;SKL-NEXT: popcntq {{.*}}, %r[[GPR0]]
+
+;ADL-LABEL:@loopdep_popcnt64
+;ADL-NOT: xor
+;ADL: popcntq
 }
 
 define i32 @loopdep_tzct32(ptr nocapture %x, ptr nocapture %y) nounwind {