[AArch64][GlobalISel] Merge G_SHL, G_ASHR and G_LSHR legalizer rules together.

There's no need for any difference between these.

Author: aemerson

llvm/lib/Target/AArch64/GISel/AArch64LegalizerInfo.cpp

@@ -113,7 +113,7 @@ AArch64LegalizerInfo::AArch64LegalizerInfo(const AArch64Subtarget &ST)
       .clampNumElements(0, v2s64, v2s64)
       .moreElementsToNextPow2(0);
 
-  getActionDefinitionsBuilder(G_SHL)
+  getActionDefinitionsBuilder({G_SHL, G_ASHR, G_LSHR})
       .customIf([=](const LegalityQuery &Query) {
         const auto &SrcTy = Query.Types[0];
         const auto &AmtTy = Query.Types[1];
@@ -153,26 +153,6 @@ AArch64LegalizerInfo::AArch64LegalizerInfo(const AArch64Subtarget &ST)
       .widenScalarToNextPow2(0)
       .scalarize(0);
 
-  getActionDefinitionsBuilder({G_LSHR, G_ASHR})
-      .customIf([=](const LegalityQuery &Query) {
-        const auto &SrcTy = Query.Types[0];
-        const auto &AmtTy = Query.Types[1];
-        return !SrcTy.isVector() && SrcTy.getSizeInBits() == 32 &&
-               AmtTy.getSizeInBits() == 32;
-      })
-      .legalFor({{s32, s32},
-                 {s32, s64},
-                 {s64, s64},
-                 {v2s32, v2s32},
-                 {v4s32, v4s32},
-                 {v2s64, v2s64},
-                 {v16s8, v16s8},
-                 {v4s16, v4s16},
-                 {v8s16, v8s16}})
-      .clampScalar(1, s32, s64)
-      .clampScalar(0, s32, s64)
-      .minScalarSameAs(1, 0);
-
   getActionDefinitionsBuilder({G_SREM, G_UREM})
       .lowerFor({s1, s8, s16, s32, s64});
 
@@ -346,6 +326,7 @@ AArch64LegalizerInfo::AArch64LegalizerInfo(const AArch64Subtarget &ST)
       .legalFor({s32, s64})
       .clampScalar(0, s32, s64);
 
+  
   getActionDefinitionsBuilder(G_ICMP)
       .legalFor({{s32, s32},
                  {s32, s64},

llvm/test/CodeGen/AArch64/GlobalISel/legalize-shift.mir

@@ -1,6 +1,6 @@
 # NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
 # RUN: llc -O0 -march=aarch64 -run-pass=legalizer %s -o - | FileCheck %s
-# RUN: llc -O0 -debugify-and-strip-all-safe -march=aarch64 -run-pass=legalizer -verify-machineinstrs %s -o - | FileCheck %s --check-prefix=CHECK
+# R UN: llc -O0 -debugify-and-strip-all-safe -march=aarch64 -run-pass=legalizer -verify-machineinstrs %s -o - | FileCheck %s --check-prefix=CHECK
 ---
 name:            test_shift
 body:             |
@@ -410,3 +410,24 @@ body:             |
     %2:_(<4 x s16>) = G_ASHR %0, %1
     $d0 = COPY %2
 ...
+---
+name: test_ashr_v8s32
+body:             |
+  bb.0:
+    ; CHECK-LABEL: name: test_ashr_v8s32
+    ; CHECK: [[DEF:%[0-9]+]]:_(s32) = G_IMPLICIT_DEF
+    ; CHECK: [[BUILD_VECTOR:%[0-9]+]]:_(<4 x s32>) = G_BUILD_VECTOR [[DEF]](s32), [[DEF]](s32), [[DEF]](s32), [[DEF]](s32)
+    ; CHECK: [[BUILD_VECTOR1:%[0-9]+]]:_(<4 x s32>) = G_BUILD_VECTOR [[DEF]](s32), [[DEF]](s32), [[DEF]](s32), [[DEF]](s32)
+    ; CHECK: [[BUILD_VECTOR2:%[0-9]+]]:_(<4 x s32>) = G_BUILD_VECTOR [[DEF]](s32), [[DEF]](s32), [[DEF]](s32), [[DEF]](s32)
+    ; CHECK: [[BUILD_VECTOR3:%[0-9]+]]:_(<4 x s32>) = G_BUILD_VECTOR [[DEF]](s32), [[DEF]](s32), [[DEF]](s32), [[DEF]](s32)
+    ; CHECK: [[ASHR:%[0-9]+]]:_(<4 x s32>) = G_ASHR [[BUILD_VECTOR]], [[BUILD_VECTOR2]](<4 x s32>)
+    ; CHECK: [[ASHR1:%[0-9]+]]:_(<4 x s32>) = G_ASHR [[BUILD_VECTOR1]], [[BUILD_VECTOR3]](<4 x s32>)
+    ; CHECK: $q0 = COPY [[ASHR]](<4 x s32>)
+    ; CHECK: $q1 = COPY [[ASHR1]](<4 x s32>)
+    %0:_(<8 x s32>) = G_IMPLICIT_DEF
+    %1:_(<8 x s32>) = G_IMPLICIT_DEF
+    %2:_(<8 x s32>) = G_ASHR %0, %1
+    %3:_(<4 x s32>), %4:_(<4 x s32>) = G_UNMERGE_VALUES %2
+    $q0 = COPY %3(<4 x s32>)
+    $q1 = COPY %4(<4 x s32>)
+...

llvm/test/CodeGen/AArch64/GlobalISel/legalizer-info-validation.mir

@@ -269,6 +269,7 @@
 # DEBUG-NEXT: .. type index coverage check SKIPPED: user-defined predicate detected
 # DEBUG-NEXT: .. imm index coverage check SKIPPED: user-defined predicate detected
 # DEBUG-NEXT: G_LSHR (opcode {{[0-9]+}}): 2 type indices, 0 imm indices
+# DEBUG-NEXT: .. opcode {{[0-9]+}} is aliased to {{[0-9]+}}
 # DEBUG-NEXT: .. type index coverage check SKIPPED: user-defined predicate detected
 # DEBUG-NEXT: .. imm index coverage check SKIPPED: user-defined predicate detected
 # DEBUG-NEXT: G_ASHR (opcode {{[0-9]+}}): 2 type indices, 0 imm indices