[Hexagon] Fix fshl/fshr -> combine() bug identified in D75114

Author: RKSimon

llvm/lib/Target/Hexagon/HexagonPatterns.td

@@ -1095,7 +1095,7 @@ def Divu64_8: SDNodeXForm<imm, [{
 // Special cases:
 let AddedComplexity = 100 in {
   def: Pat<(fshl I32:$Rs, I32:$Rt, (i32 16)),
-           (A2_combine_hl I32:$Rs, I32:$Rt)>;
+           (A2_combine_lh I32:$Rs, I32:$Rt)>;
   def: Pat<(fshl I64:$Rs, I64:$Rt, IsMul8_U3:$S),
            (S2_valignib I64:$Rs, I64:$Rt, (Divu64_8 $S))>;
 }
@@ -1129,7 +1129,7 @@ def FShr64r: OutPatFrag<(ops node:$Rs, node:$Rt, node:$Ru),
 // Special cases:
 let AddedComplexity = 100 in {
   def: Pat<(fshr I32:$Rs, I32:$Rt, (i32 16)),
-           (A2_combine_hl I32:$Rs, I32:$Rt)>;
+           (A2_combine_lh I32:$Rs, I32:$Rt)>;
   def: Pat<(fshr I64:$Rs, I64:$Rt, IsMul8_U3:$S),
            (S2_valignib I64:$Rs, I64:$Rt, (Divu8 $S))>;
 }

llvm/test/CodeGen/Hexagon/funnel-shift.ll

@@ -257,15 +257,15 @@ b0:
 }
 
 ; CHECK-LABEL: f30:
-; CHECK: r[[R00:[0-9]+]] = combine(r0.h,r1.l)
+; CHECK: r[[R00:[0-9]+]] = combine(r0.l,r1.h)
 define i32 @f30(i32 %a0, i32 %a1) #1 {
 b0:
   %v0 = tail call i32 @llvm.fshl.i32(i32 %a0, i32 %a1, i32 16)
   ret i32 %v0
 }
 
 ; CHECK-LABEL: f31:
-; CHECK: r[[R00:[0-9]+]] = combine(r0.h,r1.l)
+; CHECK: r[[R00:[0-9]+]] = combine(r0.l,r1.h)
 define i32 @f31(i32 %a0, i32 %a1) #1 {
 b0:
   %v0 = tail call i32 @llvm.fshr.i32(i32 %a0, i32 %a1, i32 16)