GlobalISel: Allow shift amount to be a different type

For AMDGPU the shift amount is never 64-bit, and
this needs to use a 32-bit shift.

X86 uses i8, but seemed to be hacking around this before.

llvm-svn: 351882

1 files changed, 13 insertions, 5 deletions

diff --git a/llvm/lib/Target/X86/X86RegisterBankInfo.cpp b/llvm/lib/Target/X86/X86RegisterBankInfo.cpp
index f8aef0c0dc3..3ea4c59aa49 100644
--- a/llvm/lib/Target/X86/X86RegisterBankInfo.cpp
+++ b/llvm/lib/Target/X86/X86RegisterBankInfo.cpp
@@ -173,17 +173,25 @@ X86RegisterBankInfo::getInstrMapping(const MachineInstr &MI) const {
   case TargetOpcode::G_ADD:
   case TargetOpcode::G_SUB:
   case TargetOpcode::G_MUL:
-  case TargetOpcode::G_SHL:
-  case TargetOpcode::G_LSHR:
-  case TargetOpcode::G_ASHR:
     return getSameOperandsMapping(MI, false);
-    break;
   case TargetOpcode::G_FADD:
   case TargetOpcode::G_FSUB:
   case TargetOpcode::G_FMUL:
   case TargetOpcode::G_FDIV:
     return getSameOperandsMapping(MI, true);
-    break;
+  case TargetOpcode::G_SHL:
+  case TargetOpcode::G_LSHR:
+  case TargetOpcode::G_ASHR: {
+    const MachineFunction &MF = *MI.getParent()->getParent();
+    const MachineRegisterInfo &MRI = MF.getRegInfo();
+
+    unsigned NumOperands = MI.getNumOperands();
+    LLT Ty = MRI.getType(MI.getOperand(0).getReg());
+
+    auto Mapping = getValueMapping(getPartialMappingIdx(Ty, false), 3);
+    return getInstructionMapping(DefaultMappingID, 1, Mapping, NumOperands);
+
+  }
   default:
     break;
   }