fixup! Add FIXMEs.

Author: topperc

llvm/test/CodeGen/RISCV/GlobalISel/iabs.ll

@@ -13,6 +13,7 @@ declare i16 @llvm.abs.i16(i16, i1 immarg)
 declare i32 @llvm.abs.i32(i32, i1 immarg)
 declare i64 @llvm.abs.i64(i64, i1 immarg)
 
+; FIXME: Could combine back to back srais.
 define i8 @abs8(i8 %x) {
 ; RV32I-LABEL: abs8:
 ; RV32I:       # %bb.0:
@@ -49,6 +50,7 @@ define i8 @abs8(i8 %x) {
   ret i8 %abs
 }
 
+; FIXME: Could combine back to back srais.
 define i16 @abs16(i16 %x) {
 ; RV32I-LABEL: abs16:
 ; RV32I:       # %bb.0:

llvm/test/CodeGen/RISCV/GlobalISel/shift.ll

@@ -47,6 +47,7 @@ define i16 @test_shl_i48(i48 %x) {
   ret i16 %trunc
 }
 
+; FIXME: Could use srlw to remove slli+srli.
 define i16 @test_lshr_i48_2(i48 %x, i48 %y) {
 ; RV32-LABEL: test_lshr_i48_2:
 ; RV32:       # %bb.0:
@@ -67,6 +68,7 @@ define i16 @test_lshr_i48_2(i48 %x, i48 %y) {
   ret i16 %trunc
 }
 
+; FIXME: Could use sraw to remove the sext.w.
 define i16 @test_ashr_i48_2(i48 %x, i48 %y) {
 ; RV32-LABEL: test_ashr_i48_2:
 ; RV32:       # %bb.0: