[AArch64][GlobalISel] Lower G_FSHL and G_FSHR.

Codegen isn't as good as we need it, but that'll be done later.

lib/Target/AArch64/GISel/AArch64LegalizerInfo.cpp

@@ -700,6 +700,8 @@ AArch64LegalizerInfo::AArch64LegalizerInfo(const AArch64Subtarget &ST)
   getActionDefinitionsBuilder({G_UADDSAT, G_USUBSAT})
       .lowerIf([=](const LegalityQuery &Q) { return Q.Types[0].isScalar(); });
 
+  getActionDefinitionsBuilder({G_FSHL, G_FSHR}).lower();
+
   computeTables();
   verify(*ST.getInstrInfo());
 }

test/CodeGen/AArch64/GlobalISel/legalize-fshl.mir

@@ -0,0 +1,66 @@
+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
+# RUN: llc -O0 -mtriple=arm64-unknown-unknown -global-isel -run-pass=legalizer -global-isel-abort=1 %s -o - | FileCheck %s
+---
+name:            test_s32
+alignment:       4
+tracksRegLiveness: true
+body:             |
+  bb.0:
+    liveins: $w0, $w1
+
+    ; CHECK-LABEL: name: test_s32
+    ; CHECK: liveins: $w0, $w1
+    ; CHECK: [[COPY:%[0-9]+]]:_(s32) = COPY $w0
+    ; CHECK: [[COPY1:%[0-9]+]]:_(s32) = COPY $w1
+    ; CHECK: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 31
+    ; CHECK: [[AND:%[0-9]+]]:_(s32) = G_AND [[COPY1]], [[C]]
+    ; CHECK: [[C1:%[0-9]+]]:_(s32) = G_CONSTANT i32 -1
+    ; CHECK: [[XOR:%[0-9]+]]:_(s32) = G_XOR [[COPY1]], [[C1]]
+    ; CHECK: [[AND1:%[0-9]+]]:_(s32) = G_AND [[XOR]], [[C]]
+    ; CHECK: [[SHL:%[0-9]+]]:_(s32) = G_SHL [[COPY]], [[AND]](s32)
+    ; CHECK: [[C2:%[0-9]+]]:_(s64) = G_CONSTANT i64 1
+    ; CHECK: [[LSHR:%[0-9]+]]:_(s32) = G_LSHR [[COPY]], [[C2]](s64)
+    ; CHECK: [[LSHR1:%[0-9]+]]:_(s32) = G_LSHR [[LSHR]], [[AND1]](s32)
+    ; CHECK: [[OR:%[0-9]+]]:_(s32) = G_OR [[SHL]], [[LSHR1]]
+    ; CHECK: $w0 = COPY [[OR]](s32)
+    ; CHECK: RET_ReallyLR implicit $w0
+    %0:_(s32) = COPY $w0
+    %1:_(s32) = COPY $w1
+    %2:_(s32) = G_FSHL %0(s32), %0, %1
+    $w0 = COPY %2(s32)
+    RET_ReallyLR implicit $w0
+
+...
+
+---
+name:            test_s64
+alignment:       4
+tracksRegLiveness: true
+body:             |
+  bb.0:
+    liveins: $x0, $x1
+
+    ; CHECK-LABEL: name: test_s64
+    ; CHECK: liveins: $x0, $x1
+    ; CHECK: [[COPY:%[0-9]+]]:_(s64) = COPY $x0
+    ; CHECK: [[COPY1:%[0-9]+]]:_(s64) = COPY $x1
+    ; CHECK: [[C:%[0-9]+]]:_(s64) = G_CONSTANT i64 63
+    ; CHECK: [[AND:%[0-9]+]]:_(s64) = G_AND [[COPY1]], [[C]]
+    ; CHECK: [[C1:%[0-9]+]]:_(s64) = G_CONSTANT i64 -1
+    ; CHECK: [[XOR:%[0-9]+]]:_(s64) = G_XOR [[COPY1]], [[C1]]
+    ; CHECK: [[AND1:%[0-9]+]]:_(s64) = G_AND [[XOR]], [[C]]
+    ; CHECK: [[C2:%[0-9]+]]:_(s64) = G_CONSTANT i64 1
+    ; CHECK: [[SHL:%[0-9]+]]:_(s64) = G_SHL [[COPY]], [[AND]](s64)
+    ; CHECK: [[LSHR:%[0-9]+]]:_(s64) = G_LSHR [[COPY]], [[C2]](s64)
+    ; CHECK: [[LSHR1:%[0-9]+]]:_(s64) = G_LSHR [[LSHR]], [[AND1]](s64)
+    ; CHECK: [[OR:%[0-9]+]]:_(s64) = G_OR [[SHL]], [[LSHR1]]
+    ; CHECK: $x0 = COPY [[OR]](s64)
+    ; CHECK: RET_ReallyLR implicit $x0
+    %0:_(s64) = COPY $x0
+    %1:_(s64) = COPY $x1
+    %2:_(s64) = G_FSHL %0(s64), %0, %1(s64)
+    $x0 = COPY %2(s64)
+    RET_ReallyLR implicit $x0
+
+...
+

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

@@ -285,11 +285,12 @@
 # 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_FSHL (opcode {{[0-9]+}}): 2 type indices, 0 imm indices
-# DEBUG-NEXT: .. type index coverage check SKIPPED: no rules defined
+# DEBUG-NEXT: .. type index coverage check SKIPPED: user-defined predicate detected
-# DEBUG-NEXT: .. imm index coverage check SKIPPED: no rules defined
+# DEBUG-NEXT: .. imm index coverage check SKIPPED: user-defined predicate detected
 # DEBUG-NEXT: G_FSHR (opcode {{[0-9]+}}): 2 type indices, 0 imm indices
-# DEBUG-NEXT: .. type index coverage check SKIPPED: no rules defined
+# DEBUG-NEXT: .. opcode {{[0-9]+}} is aliased to {{[0-9]+}}
-# DEBUG-NEXT: .. imm index coverage check SKIPPED: no rules defined
+# 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_ICMP (opcode {{[0-9]+}}): 2 type indices, 0 imm indices
 # DEBUG-NEXT: .. type index coverage check SKIPPED: user-defined predicate detected
 # DEBUG-NEXT: .. imm index coverage check SKIPPED: user-defined predicate detected