[ARM] Add fp16 addressing to isLegalT2AddressImmediate

The fp16 version of VLDR takes a imm8 multiplied by 2. This updates the costs
to account for those, and adds extra testing. It is dependant upon hasFPRegs16
as this is what the load/store instructions require.

Differential Revision: https://reviews.llvm.org/D62966

llvm-svn: 362872

2 files changed, 14 insertions, 11 deletions

diff --git a/llvm/lib/Target/ARM/ARMISelLowering.cpp b/llvm/lib/Target/ARM/ARMISelLowering.cpp
index ad84f036f24..c31056186de 100644
--- a/llvm/lib/Target/ARM/ARMISelLowering.cpp
+++ b/llvm/lib/Target/ARM/ARMISelLowering.cpp
@@ -13300,6 +13300,9 @@ static bool isLegalT2AddressImmediate(int64_t V, EVT VT,
 
   unsigned NumBytes = std::max(VT.getSizeInBits() / 8, 1U);
 
+  // half VLDR: 2 * imm8
+  if (VT.isFloatingPoint() && NumBytes == 2 && Subtarget->hasFPRegs16())
+    return isShiftedUInt<8, 1>(V);
   // VLDR and LDRD: 4 * imm8
   if ((VT.isFloatingPoint() && Subtarget->hasVFP2Base()) || NumBytes == 8)
     return isShiftedUInt<8, 2>(V);
diff --git a/llvm/test/Analysis/CostModel/ARM/gep.ll b/llvm/test/Analysis/CostModel/ARM/gep.ll
index f036b499917..c11e4518564 100644
--- a/llvm/test/Analysis/CostModel/ARM/gep.ll
+++ b/llvm/test/Analysis/CostModel/ARM/gep.ll
@@ -336,11 +336,11 @@ define void @testhalf(half* %a, i32 %i) {
 ; CHECK-MVE-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a1 = getelementptr inbounds half, half* %a, i32 1
 ; CHECK-MVE-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %am1 = getelementptr inbounds half, half* %a, i32 -1
 ; CHECK-MVE-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a255 = getelementptr inbounds half, half* %a, i32 255
-; CHECK-MVE-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a256 = getelementptr inbounds half, half* %a, i32 256
-; CHECK-MVE-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %am255 = getelementptr inbounds half, half* %a, i32 -255
+; CHECK-MVE-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %a256 = getelementptr inbounds half, half* %a, i32 256
+; CHECK-MVE-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %am255 = getelementptr inbounds half, half* %a, i32 -255
 ; CHECK-MVE-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %am256 = getelementptr inbounds half, half* %a, i32 -256
-; CHECK-MVE-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a1023 = getelementptr inbounds half, half* %a, i32 1023
-; CHECK-MVE-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a1024 = getelementptr inbounds half, half* %a, i32 1024
+; CHECK-MVE-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %a1023 = getelementptr inbounds half, half* %a, i32 1023
+; CHECK-MVE-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %a1024 = getelementptr inbounds half, half* %a, i32 1024
 ; CHECK-MVE-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %am63 = getelementptr inbounds half, half* %a, i32 -63
 ; CHECK-MVE-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %am64 = getelementptr inbounds half, half* %a, i32 -64
 ; CHECK-MVE-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %ai = getelementptr inbounds half, half* %a, i32 %i
@@ -348,15 +348,15 @@ define void @testhalf(half* %a, i32 %i) {
 ;
 ; CHECK-MVEFP-LABEL: 'testhalf'
 ; CHECK-MVEFP-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a0 = getelementptr inbounds half, half* %a, i32 0
-; CHECK-MVEFP-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %a1 = getelementptr inbounds half, half* %a, i32 1
-; CHECK-MVEFP-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %am1 = getelementptr inbounds half, half* %a, i32 -1
-; CHECK-MVEFP-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %a255 = getelementptr inbounds half, half* %a, i32 255
-; CHECK-MVEFP-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a256 = getelementptr inbounds half, half* %a, i32 256
-; CHECK-MVEFP-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %am255 = getelementptr inbounds half, half* %a, i32 -255
-; CHECK-MVEFP-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %am256 = getelementptr inbounds half, half* %a, i32 -256
+; CHECK-MVEFP-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a1 = getelementptr inbounds half, half* %a, i32 1
+; CHECK-MVEFP-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %am1 = getelementptr inbounds half, half* %a, i32 -1
+; CHECK-MVEFP-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %a255 = getelementptr inbounds half, half* %a, i32 255
+; CHECK-MVEFP-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %a256 = getelementptr inbounds half, half* %a, i32 256
+; CHECK-MVEFP-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %am255 = getelementptr inbounds half, half* %a, i32 -255
+; CHECK-MVEFP-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %am256 = getelementptr inbounds half, half* %a, i32 -256
 ; CHECK-MVEFP-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %a1023 = getelementptr inbounds half, half* %a, i32 1023
 ; CHECK-MVEFP-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %a1024 = getelementptr inbounds half, half* %a, i32 1024
-; CHECK-MVEFP-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %am63 = getelementptr inbounds half, half* %a, i32 -63
+; CHECK-MVEFP-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %am63 = getelementptr inbounds half, half* %a, i32 -63
 ; CHECK-MVEFP-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %am64 = getelementptr inbounds half, half* %a, i32 -64
 ; CHECK-MVEFP-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %ai = getelementptr inbounds half, half* %a, i32 %i
 ; CHECK-MVEFP-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: ret void