[clang] [llvm] [HLSL][DXIL] Implementation of round intrinsic (PR #83570)

[S. Bharadwaj Yadavalli via cfe-commits]

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@@ -0,0 +1,43 @@
+; RUN: opt -S -dxil-op-lower < %s | FileCheck %s
+
+; Make sure dxil operation function calls for round are generated for float and half.
+; CHECK:call float @dx.op.unary.f32(i32 26, float %{{.*}})
+; CHECK:call half @dx.op.unary.f16(i32 26, half %{{.*}})
+
+target datalayout = "e-m:e-p:32:32-i1:32-i8:8-i16:16-i32:32-i64:64-f16:16-f32:32-f64:64-n8:16:32:64"
+target triple = "dxil-pc-shadermodel6.7-library"
+
+; Function Attrs: noinline nounwind optnone
+define noundef float @_Z3foof(float noundef %a) #0 {
+entry:
+  %a.addr = alloca float, align 4
+  store float %a, ptr %a.addr, align 4
+  %0 = load float, ptr %a.addr, align 4
+  %elt.round = call float @llvm.round.f32(float %0)
+  ret float %elt.round
+}
+
+; Function Attrs: nocallback nofree nosync nounwind readnone speculatable willreturn
+declare float @llvm.round.f32(float) #1
+
+; Function Attrs: noinline nounwind optnone
+define noundef half @_Z3barDh(half noundef %a) #0 {
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bharadwajy wrote:

Consider using unmangled function name - which is `bar` here, but suggest something like `round_double` for better readability.

https://github.com/llvm/llvm-project/pull/83570