[llvm] [GISel] funnel shift combiner port from SelectionDAG ISel to GlobalISel (PR #135132)

[Axel Sorenson via llvm-commits]

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@@ -105,3 +105,53 @@ define i16 @test_shl_i48_2(i48 %x, i48 %y) {
   %trunc = trunc i48 %shl to i16
   ret i16 %trunc
 }
+
+define i16 @test_fshl_i32(i32 %x, i32 %_, i32 %y) {
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axelcool1234 wrote:


> Please refrain from force push unless it's necessary: https://www.llvm.org/docs/GitHub.html#rebasing-pull-requests-and-force-pushes. Please append new commits instead, as they're all gonna be squash into one at the end.

Woops! I apologize, I can't believe I forgot this.

> could you create two commits for this PR: the first one contains only the new test functions you added (e.g. test_fshl_i32 here) but with CHECK lines showing the unoptimized assembly code. And the second commit being your changes, in which the CHECK lines are updated with optimized code. With such, it's easier to see the changes made by your patch by comparing the differences of the CHECK lines between the two commits. The first commit is also known as "pre-commit test"

I have pushed two commits following this style, although I'm probably going to have to do it again once I introduce vector tests and (hopefully) figure out what's causing the AArch64 fshr test to not trigger the combiner.

https://github.com/llvm/llvm-project/pull/135132