[llvm] e339bba - [AArch64][GlobalISel] Fix manual selection for v4s16 and v8s8 G_DUP

[Jessica Paquette via llvm-commits]

Author: Jessica Paquette
Date: 2021-02-24T10:23:06-08:00
New Revision: e339bba637b941c8e78057319b7654c4babf18cb

URL: https://github.com/llvm/llvm-project/commit/e339bba637b941c8e78057319b7654c4babf18cb
DIFF: https://github.com/llvm/llvm-project/commit/e339bba637b941c8e78057319b7654c4babf18cb.diff

LOG: [AArch64][GlobalISel] Fix manual selection for v4s16 and v8s8 G_DUP

The manual G_DUP selection code would produce DUPv16i8 for v8s8s and DUPv8i16
for v4s16.

This adds the missing cases to the manual selection code, and makes it return
false when there is an unexpected size.

Update select-dup.mir to reflect the change.

Differential Revision: https://reviews.llvm.org/D97240

Added: 
    

Modified: 
    llvm/lib/Target/AArch64/GISel/AArch64InstructionSelector.cpp
    llvm/test/CodeGen/AArch64/GlobalISel/select-dup.mir

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Target/AArch64/GISel/AArch64InstructionSelector.cpp b/llvm/lib/Target/AArch64/GISel/AArch64InstructionSelector.cpp
index e34d18537b4d..61748e70d66f 100644
--- a/llvm/lib/Target/AArch64/GISel/AArch64InstructionSelector.cpp
+++ b/llvm/lib/Target/AArch64/GISel/AArch64InstructionSelector.cpp
@@ -3194,14 +3194,18 @@ bool AArch64InstructionSelector::select(MachineInstr &I) {
     // 
diff icult because at RBS we may end up pessimizing the fpr case if we
     // decided to add an anyextend to fix this. Manual selection is the most
     // robust solution for now.
-    Register SrcReg = I.getOperand(1).getReg();
-    if (RBI.getRegBank(SrcReg, MRI, TRI)->getID() != AArch64::GPRRegBankID)
+    if (RBI.getRegBank(I.getOperand(1).getReg(), MRI, TRI)->getID() !=
+        AArch64::GPRRegBankID)
       return false; // We expect the fpr regbank case to be imported.
-    LLT SrcTy = MRI.getType(SrcReg);
-    if (SrcTy.getSizeInBits() == 16)
-      I.setDesc(TII.get(AArch64::DUPv8i16gpr));
-    else if (SrcTy.getSizeInBits() == 8)
+    LLT VecTy = MRI.getType(I.getOperand(0).getReg());
+    if (VecTy == LLT::vector(8, 8))
+      I.setDesc(TII.get(AArch64::DUPv8i8gpr));
+    else if (VecTy == LLT::vector(16, 8))
       I.setDesc(TII.get(AArch64::DUPv16i8gpr));
+    else if (VecTy == LLT::vector(4, 16))
+      I.setDesc(TII.get(AArch64::DUPv4i16gpr));
+    else if (VecTy == LLT::vector(8, 16))
+      I.setDesc(TII.get(AArch64::DUPv8i16gpr));
     else
       return false;
     return constrainSelectedInstRegOperands(I, TII, TRI, RBI);

diff  --git a/llvm/test/CodeGen/AArch64/GlobalISel/select-dup.mir b/llvm/test/CodeGen/AArch64/GlobalISel/select-dup.mir
index be01e0c34758..cc2a2fdf4c69 100644
--- a/llvm/test/CodeGen/AArch64/GlobalISel/select-dup.mir
+++ b/llvm/test/CodeGen/AArch64/GlobalISel/select-dup.mir
@@ -246,6 +246,28 @@ body:             |
     $q0 = COPY %dup(<8 x s16>)
     RET_ReallyLR implicit $q0
 
+...
+---
+name:            DUPv4s16gpr_s16_src
+alignment:       4
+legalized:       true
+regBankSelected: true
+tracksRegLiveness: true
+body:             |
+  bb.0.entry:
+    liveins: $w0
+    ; CHECK-LABEL: name: DUPv4s16gpr_s16_src
+    ; CHECK: liveins: $w0
+    ; CHECK: %copy:gpr32 = COPY $w0
+    ; CHECK: %dup:fpr64 = DUPv4i16gpr %copy
+    ; CHECK: $d0 = COPY %dup
+    ; CHECK: RET_ReallyLR implicit $d0
+    %copy:gpr(s32) = COPY $w0
+    %trunc:gpr(s16) = G_TRUNC %copy
+    %dup:fpr(<4 x s16>) = G_DUP %trunc(s16)
+    $d0 = COPY %dup(<4 x s16>)
+    RET_ReallyLR implicit $d0
+
 ...
 ---
 name:            DUPv8i8gpr
@@ -267,6 +289,28 @@ body:             |
     $d0 = COPY %dup(<8 x s8>)
     RET_ReallyLR implicit $d0
 
+...
+---
+name:            DUPv8i8gpr_s8_src
+alignment:       4
+legalized:       true
+regBankSelected: true
+tracksRegLiveness: true
+body:             |
+  bb.0.entry:
+    liveins: $w0
+    ; CHECK-LABEL: name: DUPv8i8gpr_s8_src
+    ; CHECK: liveins: $w0
+    ; CHECK: %copy:gpr32 = COPY $w0
+    ; CHECK: %dup:fpr64 = DUPv8i8gpr %copy
+    ; CHECK: $d0 = COPY %dup
+    ; CHECK: RET_ReallyLR implicit $d0
+    %copy:gpr(s32) = COPY $w0
+    %trunc:gpr(s8) = G_TRUNC %copy(s32)
+    %dup:fpr(<8 x s8>) = G_DUP %trunc(s8)
+    $d0 = COPY %dup(<8 x s8>)
+    RET_ReallyLR implicit $d0
+
 ...
 ---
 name:            DUPv16i8gpr