[PATCH] D126589: Add test cases showing missed opportunity to use slli.uw or shXadd.uw. NFC

[Craig Topper via Phabricator via llvm-commits]

This revision was not accepted when it landed; it landed in state "Needs Review".
This revision was landed with ongoing or failed builds.
This revision was automatically updated to reflect the committed changes.
Closed by commit rGe642d0ea2158: [RISCV] Add test cases showing missed opportunity to use shXadd.uw. NFC (authored by craig.topper).

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D126589/new/

https://reviews.llvm.org/D126589

Files:
  llvm/test/CodeGen/RISCV/rv64zba.ll


Index: llvm/test/CodeGen/RISCV/rv64zba.ll
===================================================================
--- llvm/test/CodeGen/RISCV/rv64zba.ll
+++ llvm/test/CodeGen/RISCV/rv64zba.ll
@@ -1163,3 +1163,56 @@
   %1 = ashr i32 %ext, 9
   ret i32 %1
 }
+
+; This the IR you get from InstCombine if take the difference of 2 pointers and
+; cast is to unsigned before using as an index.
+define signext i16 @sh1adduw_ptrdiff(i64 %diff, i16* %baseptr) {
+; CHECK-LABEL: sh1adduw_ptrdiff:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    li a2, 1
+; CHECK-NEXT:    slli a2, a2, 33
+; CHECK-NEXT:    addi a2, a2, -2
+; CHECK-NEXT:    and a0, a0, a2
+; CHECK-NEXT:    add a0, a1, a0
+; CHECK-NEXT:    lh a0, 0(a0)
+; CHECK-NEXT:    ret
+  %ptrdiff = lshr exact i64 %diff, 1
+  %cast = and i64 %ptrdiff, 4294967295
+  %ptr = getelementptr inbounds i16, i16* %baseptr, i64 %cast
+  %res = load i16, i16* %ptr
+  ret i16 %res
+}
+
+define signext i32 @sh2adduw_ptrdiff(i64 %diff, i32* %baseptr) {
+; CHECK-LABEL: sh2adduw_ptrdiff:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    li a2, 1
+; CHECK-NEXT:    slli a2, a2, 34
+; CHECK-NEXT:    addi a2, a2, -4
+; CHECK-NEXT:    and a0, a0, a2
+; CHECK-NEXT:    add a0, a1, a0
+; CHECK-NEXT:    lw a0, 0(a0)
+; CHECK-NEXT:    ret
+  %ptrdiff = lshr exact i64 %diff, 2
+  %cast = and i64 %ptrdiff, 4294967295
+  %ptr = getelementptr inbounds i32, i32* %baseptr, i64 %cast
+  %res = load i32, i32* %ptr
+  ret i32 %res
+}
+
+define i64 @sh3adduw_ptrdiff(i64 %diff, i64* %baseptr) {
+; CHECK-LABEL: sh3adduw_ptrdiff:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    li a2, 1
+; CHECK-NEXT:    slli a2, a2, 35
+; CHECK-NEXT:    addi a2, a2, -8
+; CHECK-NEXT:    and a0, a0, a2
+; CHECK-NEXT:    add a0, a1, a0
+; CHECK-NEXT:    ld a0, 0(a0)
+; CHECK-NEXT:    ret
+  %ptrdiff = lshr exact i64 %diff, 3
+  %cast = and i64 %ptrdiff, 4294967295
+  %ptr = getelementptr inbounds i64, i64* %baseptr, i64 %cast
+  %res = load i64, i64* %ptr
+  ret i64 %res
+}


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