[llvm] [VectorCombine] Add a cost model for shuffleToIdentity. (PR #93937)

[David Green via llvm-commits]

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@@ -0,0 +1,66 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
+; RUN: opt -passes=vector-combine -S %s | FileCheck %s
+
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
+target triple = "x86_64--linux-gnu"
+
+define void @test_op_pblend_b_0_avx(ptr %l8, ptr %lop_pblend_b_0) "target-cpu"="corei7-avx" {
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davemgreen wrote:

I've added them. The core-avx2 is also not transformed. The identity concat's still cost 4 (it was 8 for corei7-avx, free without a -mcpu).

https://github.com/llvm/llvm-project/pull/93937