[llvm] [AMDGPU] - Add s_bitreplicate intrinsic (PR #69209)

[Jay Foad via llvm-commits]

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@@ -0,0 +1,45 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 2
+; RUN: llc -march=amdgcn -mcpu=gfx1100 -amdgpu-enable-delay-alu=0 -global-isel=1 -verify-machineinstrs < %s | FileCheck  -check-prefixes=GFX11 %s
+; RUN: llc -march=amdgcn -mcpu=gfx1100 -amdgpu-enable-delay-alu=0 -global-isel=0 -verify-machineinstrs < %s | FileCheck  -check-prefixes=GFX11 %s
+
+declare i64 @llvm.amdgcn.s.bitreplicate(i32)
+
+define i64 @test_s_bitreplicate_constant() {
+; GFX11-LABEL: test_s_bitreplicate_constant:
+; GFX11:       ; %bb.0: ; %entry
+; GFX11-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
+; GFX11-NEXT:    s_bitreplicate_b64_b32 s[0:1], 0x85fe3a92
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jayfoad wrote:

As a follow up you could implement constant folding for this in `lib/Analysis/ConstantFolding.cpp`.

https://github.com/llvm/llvm-project/pull/69209