[X86] Add custom code to EVEX to VEX pass to turn unmasked 128-bit VPALIGND/Q into...

This will enable us to prefer VALIGND/Q during shuffle lowering in order to get the extended register encoding space when BWI isn't available. But if we end up not using the extended registers we can switch VPALIGNR for the shorter VEX encoding.

Differential Revision: https://reviews.llvm.org/D39401

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@317122 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/X86/X86EvexToVex.cpp b/lib/Target/X86/X86EvexToVex.cpp
index 440efa3a2b76304c94b2acaba4149f518a187ac2..744510a3a3ba635ed98127e76d07b53b6f105e0f 100644 (file)
--- a/lib/Target/X86/X86EvexToVex.cpp
+++ b/lib/Target/X86/X86EvexToVex.cpp
@@ -163,6 +163,25 @@ static bool usesExtendedRegister(const MachineInstr &MI) {
   return false;
 }
 
+// Do any custom cleanup needed to finalize the conversion.
+static void performCustomAdjustments(MachineInstr &MI, unsigned NewOpc) {
+  (void)NewOpc;
+  unsigned Opc = MI.getOpcode();
+  switch (Opc) {
+  case X86::VALIGNDZ128rri:
+  case X86::VALIGNDZ128rmi:
+  case X86::VALIGNQZ128rri:
+  case X86::VALIGNQZ128rmi:
+    assert((NewOpc == X86::VPALIGNRrri || NewOpc == X86::VPALIGNRrmi) &&
+           "Unexpected new opcode!");
+    unsigned Scale = (Opc == X86::VALIGNQZ128rri ||
+                      Opc == X86::VALIGNQZ128rmi) ? 8 : 4;
+    MachineOperand &Imm = MI.getOperand(MI.getNumExplicitOperands()-1);
+    Imm.setImm(Imm.getImm() * Scale);
+    break;
+  }
+}
+
 
 // For EVEX instructions that can be encoded using VEX encoding
 // replace them by the VEX encoding in order to reduce size.
@@ -223,6 +242,8 @@ bool EvexToVexInstPass::CompressEvexToVexImpl(MachineInstr &MI) const {
   if (usesExtendedRegister(MI))
     return false;
 
+  performCustomAdjustments(MI, NewOpc);
+
   MI.setDesc(TII->get(NewOpc));
   MI.setAsmPrinterFlag(AC_EVEX_2_VEX);
   return true;

diff --git a/test/CodeGen/X86/avx512vl-intrinsics-upgrade.ll b/test/CodeGen/X86/avx512vl-intrinsics-upgrade.ll
index 992c4a10887bf8ced330f26995411325618013e1..b6723ee50b0595af660c691ad0eb20d2877f1ec6 100644 (file)
--- a/test/CodeGen/X86/avx512vl-intrinsics-upgrade.ll
+++ b/test/CodeGen/X86/avx512vl-intrinsics-upgrade.ll
@@ -4689,8 +4689,8 @@ declare <4 x i32> @llvm.x86.avx512.mask.valign.d.128(<4 x i32>, <4 x i32>, i32,
 define <4 x i32>@test_int_x86_avx512_mask_valign_d_128(<4 x i32> %x0, <4 x i32> %x1,<4 x i32> %x3, i8 %x4) {
 ; CHECK-LABEL: test_int_x86_avx512_mask_valign_d_128:
 ; CHECK:       ## BB#0:
-; CHECK-NEXT:    valignd $2, %xmm1, %xmm0, %xmm3 ## encoding: [0x62,0xf3,0x7d,0x08,0x03,0xd9,0x02]
-; CHECK-NEXT:    ## xmm3 = xmm1[2,3],xmm0[0,1]
+; CHECK-NEXT:    vpalignr $8, %xmm1, %xmm0, %xmm3 ## EVEX TO VEX Compression encoding: [0xc4,0xe3,0x79,0x0f,0xd9,0x08]
+; CHECK-NEXT:    ## xmm3 = xmm1[8,9,10,11,12,13,14,15],xmm0[0,1,2,3,4,5,6,7]
 ; CHECK-NEXT:    kmovw %edi, %k1 ## encoding: [0xc5,0xf8,0x92,0xcf]
 ; CHECK-NEXT:    valignd $2, %xmm1, %xmm0, %xmm2 {%k1} ## encoding: [0x62,0xf3,0x7d,0x09,0x03,0xd1,0x02]
 ; CHECK-NEXT:    ## xmm2 {%k1} = xmm1[2,3],xmm0[0,1]
@@ -4730,8 +4730,8 @@ declare <2 x i64> @llvm.x86.avx512.mask.valign.q.128(<2 x i64>, <2 x i64>, i32,
 define <2 x i64>@test_int_x86_avx512_mask_valign_q_128(<2 x i64> %x0, <2 x i64> %x1, <2 x i64> %x3, i8 %x4) {
 ; CHECK-LABEL: test_int_x86_avx512_mask_valign_q_128:
 ; CHECK:       ## BB#0:
-; CHECK-NEXT:    valignq $1, %xmm1, %xmm0, %xmm3 ## encoding: [0x62,0xf3,0xfd,0x08,0x03,0xd9,0x01]
-; CHECK-NEXT:    ## xmm3 = xmm1[1],xmm0[0]
+; CHECK-NEXT:    vpalignr $8, %xmm1, %xmm0, %xmm3 ## EVEX TO VEX Compression encoding: [0xc4,0xe3,0x79,0x0f,0xd9,0x08]
+; CHECK-NEXT:    ## xmm3 = xmm1[8,9,10,11,12,13,14,15],xmm0[0,1,2,3,4,5,6,7]
 ; CHECK-NEXT:    kmovw %edi, %k1 ## encoding: [0xc5,0xf8,0x92,0xcf]
 ; CHECK-NEXT:    valignq $1, %xmm1, %xmm0, %xmm2 {%k1} ## encoding: [0x62,0xf3,0xfd,0x09,0x03,0xd1,0x01]
 ; CHECK-NEXT:    ## xmm2 {%k1} = xmm1[1],xmm0[0]

diff --git a/utils/TableGen/X86EVEX2VEXTablesEmitter.cpp b/utils/TableGen/X86EVEX2VEXTablesEmitter.cpp
index 7c2d4efa29b3f64085a988f1685faa6d276a3451..848e59c079039c9aceadb43482223111b4579dd4 100644 (file)
--- a/utils/TableGen/X86EVEX2VEXTablesEmitter.cpp
+++ b/utils/TableGen/X86EVEX2VEXTablesEmitter.cpp
@@ -148,7 +148,13 @@ void X86EVEX2VEXTablesEmitter::printTable(const std::vector<Entry> &Table,
       {"VINSERTF64x2Z256rm",  "VINSERTF128rm",   false},
       {"VINSERTF64x2Z256rr",  "VINSERTF128rr",   false},
       {"VINSERTI64x2Z256rm",  "VINSERTI128rm",   false},
-      {"VINSERTI64x2Z256rr",  "VINSERTI128rr",   false}
+      {"VINSERTI64x2Z256rr",  "VINSERTI128rr",   false},
+
+      // These will require some custom adjustment in the conversion pass.
+      {"VALIGNDZ128rri",      "VPALIGNRrri",     true},
+      {"VALIGNQZ128rri",      "VPALIGNRrri",     true},
+      {"VALIGNDZ128rmi",      "VPALIGNRrmi",     true},
+      {"VALIGNQZ128rmi",      "VPALIGNRrmi",     true},
   };
 
   // Print the manually added entries