[llvm] [RISCV] Add initial support of memcmp expansion (PR #107548)

[Philip Reames via llvm-commits]

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@@ -0,0 +1,932 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 5
+; RUN: sed 's/iXLen/i32/g' %s | llc -mtriple=riscv32 -O2 | FileCheck %s --check-prefix=CHECK-ALIGNED-RV32
+; RUN: sed 's/iXLen/i64/g' %s | llc -mtriple=riscv64 -O2 | FileCheck %s --check-prefix=CHECK-ALIGNED-RV64
+; RUN: sed 's/iXLen/i32/g' %s | llc -mtriple=riscv32 -mattr=+unaligned-scalar-mem -O2 \
+; RUN:   | FileCheck %s --check-prefix=CHECK-UNALIGNED-RV32
+; RUN: sed 's/iXLen/i64/g' %s | llc -mtriple=riscv64 -mattr=+unaligned-scalar-mem -O2 \
+; RUN:   | FileCheck %s --check-prefix=CHECK-UNALIGNED-RV64
+
+declare i32 @bcmp(i8*, i8*, iXLen) nounwind readonly
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preames wrote:

Please add coverage for the following cases:
* Length = 0, 1, 2, 3, 4, 5, 6, 7,8,16, 32, 64, runtime
* memcmp *without* comparison against zero
* RUN lines for vector

Once done, please land the tests so that we can see current expansions.

https://github.com/llvm/llvm-project/pull/107548