AMDGPU: Clear the bits before they are being set in program resource registers

Change by Tony Tye

llvm-svn: 342270
diff --git a/llvm/lib/Target/AMDGPU/Utils/AMDKernelCodeTInfo.h b/llvm/lib/Target/AMDGPU/Utils/AMDKernelCodeTInfo.h
index 9f0a4d2..82ffdef 100644
--- a/llvm/lib/Target/AMDGPU/Utils/AMDKernelCodeTInfo.h
+++ b/llvm/lib/Target/AMDGPU/Utils/AMDKernelCodeTInfo.h
@@ -46,6 +46,7 @@
    int64_t Value = 0; \
    if (!expectAbsExpression(MCParser, Value, Err)) \
      return false; \
+   C.compute_pgm_resource_registers &= ~(SetMacro(0xFFFFFFFFFFFFFFFFULL) << Shift); \
    C.compute_pgm_resource_registers |= SetMacro(Value) << Shift; \
    return true; \
 }