[AMDGPU] Ensure divergence for v_alignbit

Change-Id: I23095fdd5e9fca5229ca042d757d30cd276e2397

Author: jrbyrnes

llvm/lib/Target/AMDGPU/SIInstructions.td

@@ -2412,11 +2412,11 @@ def : AMDGPUPat <
 
 def : ROTRPattern <V_ALIGNBIT_B32_e64>;
 
-def : GCNPat<(i32 (trunc (srl i64:$src0, (and i32:$src1, (i32 31))))),
+def : GCNPat<(i32 (DivergentUnaryFrag<trunc> (srl i64:$src0, (and i32:$src1, (i32 31))))),
           (V_ALIGNBIT_B32_e64 (i32 (EXTRACT_SUBREG (i64 $src0), sub1)),
                           (i32 (EXTRACT_SUBREG (i64 $src0), sub0)), $src1)>;
 
-def : GCNPat<(i32 (trunc (srl i64:$src0, (i32 ShiftAmt32Imm:$src1)))),
+def : GCNPat<(i32 (DivergentUnaryFrag<trunc> (srl i64:$src0, (i32 ShiftAmt32Imm:$src1)))),
           (V_ALIGNBIT_B32_e64 (i32 (EXTRACT_SUBREG (i64 $src0), sub1)),
                           (i32 (EXTRACT_SUBREG (i64 $src0), sub0)), $src1)>;