[X86][AVX512] Add support for variable ASHR v2i64/v4i64 support without VLX

Use v8i64 variable ASHR instructions if we don't have VLX.

This is a reduced version of D28537 that just adds support for variable shifts - I'll continue with that patch (for just constant/uniform shifts) once I've fixed the type legalization issue in avx512-cvt.ll.

Differential Revision: https://reviews.llvm.org/D28604

llvm-svn: 291901

2 files changed, 16 insertions, 12 deletions

diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index 8a054462e5f..886782e49c5 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -21346,7 +21346,7 @@ static bool SupportedVectorVarShift(MVT VT, const X86Subtarget &Subtarget,
   if (VT.getScalarSizeInBits() == 16 && !Subtarget.hasBWI())
     return false;
 
-  if (VT.is512BitVector() || Subtarget.hasVLX())
+  if (Subtarget.hasAVX512())
     return true;
 
   bool LShift = VT.is128BitVector() || VT.is256BitVector();
diff --git a/llvm/lib/Target/X86/X86InstrAVX512.td b/llvm/lib/Target/X86/X86InstrAVX512.td
index 230d1700b8d..a473073ead2 100644
--- a/llvm/lib/Target/X86/X86InstrAVX512.td
+++ b/llvm/lib/Target/X86/X86InstrAVX512.td
@@ -4932,6 +4932,7 @@ multiclass avx512_var_shift_mb<bits<8> opc, string OpcodeStr, SDNode OpNode,
                     SSE_INTSHIFT_ITINS_P.rm>, AVX5128IBase, EVEX_B,
                     EVEX_4V, EVEX_CD8<_.EltSize, CD8VF>;
 }
+
 multiclass avx512_var_shift_sizes<bits<8> opc, string OpcodeStr, SDNode OpNode,
                                   AVX512VLVectorVTInfo _> {
   let Predicates  = [HasAVX512] in
@@ -4955,12 +4956,13 @@ multiclass avx512_var_shift_types<bits<8> opc, string OpcodeStr,
 }
 
 // Use 512bit version to implement 128/256 bit in case NoVLX.
-multiclass avx512_var_shift_w_lowering<AVX512VLVectorVTInfo _, SDNode OpNode> {
-  let Predicates = [HasBWI, NoVLX] in {
+multiclass avx512_var_shift_lowering<AVX512VLVectorVTInfo _, string OpcodeStr,
+                                     SDNode OpNode, list<Predicate> p> {
+  let Predicates = p in {
   def : Pat<(_.info256.VT (OpNode (_.info256.VT _.info256.RC:$src1),
                                   (_.info256.VT _.info256.RC:$src2))),
             (EXTRACT_SUBREG
-                (!cast<Instruction>(NAME#"WZrr")
+                (!cast<Instruction>(OpcodeStr#"Zrr")
                     (INSERT_SUBREG (_.info512.VT (IMPLICIT_DEF)), VR256X:$src1, sub_ymm),
                     (INSERT_SUBREG (_.info512.VT (IMPLICIT_DEF)), VR256X:$src2, sub_ymm)),
              sub_ymm)>;
@@ -4968,13 +4970,12 @@ multiclass avx512_var_shift_w_lowering<AVX512VLVectorVTInfo _, SDNode OpNode> {
   def : Pat<(_.info128.VT (OpNode (_.info128.VT _.info128.RC:$src1),
                                   (_.info128.VT _.info128.RC:$src2))),
             (EXTRACT_SUBREG
-                (!cast<Instruction>(NAME#"WZrr")
+                (!cast<Instruction>(OpcodeStr#"Zrr")
                     (INSERT_SUBREG (_.info512.VT (IMPLICIT_DEF)), VR128X:$src1, sub_xmm),
                     (INSERT_SUBREG (_.info512.VT (IMPLICIT_DEF)), VR128X:$src2, sub_xmm)),
              sub_xmm)>;
   }
 }
-
 multiclass avx512_var_shift_w<bits<8> opc, string OpcodeStr,
                                  SDNode OpNode> {
   let Predicates = [HasBWI] in
@@ -4990,19 +4991,22 @@ multiclass avx512_var_shift_w<bits<8> opc, string OpcodeStr,
 }
 
 defm VPSLLV : avx512_var_shift_types<0x47, "vpsllv", shl>,
-              avx512_var_shift_w<0x12, "vpsllvw", shl>,
-              avx512_var_shift_w_lowering<avx512vl_i16_info, shl>;
+              avx512_var_shift_w<0x12, "vpsllvw", shl>;
 
 defm VPSRAV : avx512_var_shift_types<0x46, "vpsrav", sra>,
-              avx512_var_shift_w<0x11, "vpsravw", sra>,
-              avx512_var_shift_w_lowering<avx512vl_i16_info, sra>;
+              avx512_var_shift_w<0x11, "vpsravw", sra>;
 
 defm VPSRLV : avx512_var_shift_types<0x45, "vpsrlv", srl>,
-              avx512_var_shift_w<0x10, "vpsrlvw", srl>,
-              avx512_var_shift_w_lowering<avx512vl_i16_info, srl>;
+              avx512_var_shift_w<0x10, "vpsrlvw", srl>;
+
 defm VPRORV : avx512_var_shift_types<0x14, "vprorv", rotr>;
 defm VPROLV : avx512_var_shift_types<0x15, "vprolv", rotl>;
 
+defm : avx512_var_shift_lowering<avx512vl_i64_info, "VPSRAVQ", sra, [HasAVX512, NoVLX]>;
+defm : avx512_var_shift_lowering<avx512vl_i16_info, "VPSLLVW", shl, [HasBWI, NoVLX]>;
+defm : avx512_var_shift_lowering<avx512vl_i16_info, "VPSRAVW", sra, [HasBWI, NoVLX]>;
+defm : avx512_var_shift_lowering<avx512vl_i16_info, "VPSRLVW", srl, [HasBWI, NoVLX]>;
+
 // Special handing for handling VPSRAV intrinsics.
 multiclass avx512_var_shift_int_lowering<string InstrStr, X86VectorVTInfo _,
                                          list<Predicate> p> {