[llvm] [MachineSink] Add option for aggressive loop sinking (PR #117247)

[Matt Arsenault via llvm-commits]

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@@ -0,0 +1,20 @@
+; RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx942 --aggressively-sink-insts-to-avoid-spills=1  < %s | FileCheck -check-prefix=SUNK %s
+
+; Check that various edge cases do not crash the compiler
+
+; Multiple uses of sunk valu, chain of sink candidates
+
+define half @global_agent_atomic_fmin_ret_f16__amdgpu_no_fine_grained_memory(ptr addrspace(1) %ptr, half %val) {
+; SUNK-LABEL: global_agent_atomic_fmin_ret_f16__amdgpu_no_fine_grained_memory:
+  %result = atomicrmw fmin ptr addrspace(1) %ptr, half %val syncscope("agent") seq_cst
+  ret half %result
+}
+
+; Sink candidates with multiple defs
+
+define void @memmove_p5_p5(ptr addrspace(5) align 1 %dst, ptr addrspace(5) align 1 readonly %src, i64 %sz) {
+; SUNK-LABEL: memmove_p5_p5:
+entry:
+  tail call void @llvm.memmove.p5.p5.i64(ptr addrspace(5) noundef nonnull align 1 %dst, ptr addrspace(5) noundef nonnull align 1 %src, i64 %sz, i1 false)
+  ret void
+}
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arsenm wrote:

Can you add a test ensuring convergent operations aren't sunk in this situation 

https://github.com/llvm/llvm-project/pull/117247