Add assume LLVM intrinsic.

Author: maleadt

src/device/llvm.jl

@@ -1,3 +1,9 @@
 # wrappers for LLVM-specific functionality
 
 @inline trap() = ccall("llvm.trap", llvmcall, Cvoid, ())
+
+@inline assume(cond::Bool) =
+    Base.llvmcall(("declare void @llvm.assume(i1)",
+                    "%cond = icmp eq i8 %0, 1
+                     call void @llvm.assume(i1 %cond)
+                     ret void"), Nothing, Tuple{Bool}, cond)

test/device/codegen.jl

@@ -85,6 +85,17 @@ end
     @test cpu(input) == gpu(input)
 end
 
+@testset "assume" begin
+    foo(i) = cld(42, i)
+    ir = sprint(io->CUDAnative.code_llvm(io, foo, Tuple{Int}))
+    @test occursin("@ptx_report_exception", ir)
+
+
+    bar(i) = (CUDAnative.assume(i > 0); cld(42, i))
+    ir = sprint(io->CUDAnative.code_llvm(io, bar, Tuple{Int}))
+    @test !occursin("@ptx_report_exception", ir)
+end
+
 end
 
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