[PATCH] D157603: [RISCV] Truncate constants to EleSize when combine store of BUILD_VECTOR

Thu Aug 10 04:52:05 PDT 2023

wangpc added inline comments.

================
Comment at: llvm/test/CodeGen/RISCV/rvv/pr64588.ll:10
+; CHECK-NEXT:    ret
+  %v = insertelement <64 x i64> zeroinitializer, i64 0, i32 1
+  %trunc = trunc <64 x i64> %v to <64 x i1>
----------------
There is still a problem here that this `insertelement` is discarded somehow:
```
Initial selection DAG: %bb.0 'bar:'
SelectionDAG has 19 nodes:
  t0: ch,glue = EntryToken
  t2: i64,ch = CopyFromReg t0, Register:i64 %0
  t4: i64,ch = CopyFromReg t0, Register:i64 %1
  t7: i32 = Constant<1>
            t6: v64i64 = BUILD_VECTOR Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>
          t9: v64i64 = insert_vector_elt t6, Constant:i64<0>, Constant:i64<1>
        t10: v64i1 = truncate t9
      t14: ch = store<(store (s64) into %ir.p11)> t0, t10, t2, undef:i64
      t16: v8i8 = BUILD_VECTOR Constant:i8<0>, Constant:i8<0>, Constant:i8<0>, Constant:i8<0>, Constant:i8<0>, Constant:i8<0>, Constant:i8<0>, Constant:i8<0>
      t12: i64 = add t2, Constant:i64<8>
    t17: ch = store<(store (s64) into %ir.p2)> t14, t16, t12, undef:i64
  t18: ch = RISCVISD::RET_GLUE t17

Combining: t18: ch = RISCVISD::RET_GLUE t17

Combining: t17: ch = store<(store (s64) into %ir.p2)> t14, t16, t12, undef:i64
Creating new node: t19: ch = store<(store (s64) into %ir.p2)> t0, t16, t12, undef:i64
Creating new node: t20: ch = TokenFactor t14, t19

Replacing.1 t17: ch = store<(store (s64) into %ir.p2)> t14, t16, t12, undef:i64

With: t20: ch = TokenFactor t14, t19
 and 0 other values

Combining: t19: ch = store<(store (s64) into %ir.p2)> t0, t16, t12, undef:i64
Creating new node: t21: ch = store<(store (s64) into %ir.p2)> t0, Constant:i64<0>, t12, undef:i64
 ... into: t21: ch = store<(store (s64) into %ir.p2)> t0, Constant:i64<0>, t12, undef:i64

Combining: t21: ch = store<(store (s64) into %ir.p2)> t0, Constant:i64<0>, t12, undef:i64

Combining: t20: ch = TokenFactor t14, t21

Combining: t18: ch = RISCVISD::RET_GLUE t20

Combining: t14: ch = store<(store (s64) into %ir.p11)> t0, t10, t2, undef:i64

Combining: t13: i64 = undef

Combining: t12: i64 = add t2, Constant:i64<8>

Combining: t11: i64 = Constant<8>

Combining: t10: v64i1 = truncate t9
Creating new node: t22: v64i1 = BUILD_VECTOR Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>

Replacing.2 t10: v64i1 = truncate t9

With: t22: v64i1 = BUILD_VECTOR Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>

Combining: t22: v64i1 = BUILD_VECTOR Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>, Constant:i64<0>

Combining: t14: ch = store<(store (s64) into %ir.p11)> t0, t22, t2, undef:i64
Creating new node: t23: ch = store<(store (s64) into %ir.p11)> t0, Constant:i64<0>, t2, undef:i64
 ... into: t23: ch = store<(store (s64) into %ir.p11)> t0, Constant:i64<0>, t2, undef:i64

Combining: t13: i64 = undef

Combining: t23: ch = store<(store (s64) into %ir.p11)> t0, Constant:i64<0>, t2, undef:i64

Combining: t20: ch = TokenFactor t23, t21

Combining: t5: i64 = Constant<0>

Combining: t2: i64,ch = CopyFromReg t0, Register:i64 %0

Combining: t1: i64 = Register %0

Combining: t0: ch,glue = EntryToken
Optimized lowered selection DAG: %bb.0 'bar:'
SelectionDAG has 11 nodes:
  t0: ch,glue = EntryToken
  t2: i64,ch = CopyFromReg t0, Register:i64 %0
      t23: ch = store<(store (s64) into %ir.p11)> t0, Constant:i64<0>, t2, undef:i64
        t12: i64 = add t2, Constant:i64<8>
      t21: ch = store<(store (s64) into %ir.p2)> t0, Constant:i64<0>, t12, undef:i64
    t20: ch = TokenFactor t23, t21
  t18: ch = RISCVISD::RET_GLUE t20
```

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D157603/new/

https://reviews.llvm.org/D157603