[llvm] [RFC][SPIR-V] Add llvm.arbitrary.fp.convert intrinsic (PR #164252)

[Matt Arsenault via llvm-commits]

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@@ -0,0 +1,66 @@
+; RUN: split-file %s %t
+; RUN: not opt -S -passes=verify %t/bad-result.ll 2>&1 | FileCheck %s --check-prefix=BADRESULT
+; RUN: not opt -S -passes=verify %t/bad-rounding.ll 2>&1 | FileCheck %s --check-prefix=BADROUND
+; RUN: not opt -S -passes=verify %t/bad-saturation.ll 2>&1 | FileCheck %s --check-prefix=BADSAT
+; RUN: opt -S -passes=verify %t/good.ll
+
+;--- bad-result.ll
+; BADRESULT: result interpretation metadata string must not be empty
+declare half @llvm.arbitrary.fp.convert.half.i8(i8, metadata, metadata, metadata, i32)
+
+define half @bad_result(i8 %v) {
+  %r = call half @llvm.arbitrary.fp.convert.half.i8(
+      i8 %v, metadata !"", metadata !"spv.E5M2EXT", metadata !"none", i32 0)
+  ret half %r
+}
+
+;--- bad-rounding.ll
+; BADROUND: unsupported rounding mode argument
+declare i8 @llvm.arbitrary.fp.convert.i8.half(half, metadata, metadata, metadata, i32)
+
+define i8 @bad_rounding(half %v) {
+  %r = call i8 @llvm.arbitrary.fp.convert.i8.half(
+      half %v, metadata !"spv.E4M3EXT", metadata !"none", metadata !"round.dynamic", i32 0)
+  ret i8 %r
+}
+
+;--- bad-saturation.ll
+; BADSAT: saturation operand must be 0 or 1
+declare i8 @llvm.arbitrary.fp.convert.i8.half.sat(half, metadata, metadata, metadata, i32)
+
+define i8 @bad_saturation(half %v) {
+  %r = call i8 @llvm.arbitrary.fp.convert.i8.half.sat(
+      half %v, metadata !"spv.E4M3EXT", metadata !"none", metadata !"round.towardzero", i32 2)
+  ret i8 %r
+}
+
+;--- good.ll
+declare half @llvm.arbitrary.fp.convert.half.i8(i8, metadata, metadata, metadata, i32)
+declare i8 @llvm.arbitrary.fp.convert.i8.half(half, metadata, metadata, metadata, i32)
+declare i32 @llvm.arbitrary.fp.convert.i32.i8(i8, metadata, metadata, metadata, i32)
+declare i8 @llvm.arbitrary.fp.convert.i8.i32(i32, metadata, metadata, metadata, i32)
+
+define half @good_from(i8 %v) {
+  %r = call half @llvm.arbitrary.fp.convert.half.i8(
+      i8 %v, metadata !"none", metadata !"spv.E4M3EXT", metadata !"none", i32 0)
+  ret half %r
+}
+
+define i8 @good_to(half %v) {
+  %r = call i8 @llvm.arbitrary.fp.convert.i8.half(
+      half %v, metadata !"spv.E4M3EXT", metadata !"none", metadata !"round.towardzero", i32 0)
+  ret i8 %r
+}
+
+; Test integer conversions with rounding modes - these are now allowed
+define i32 @good_int_rounding(i8 %v) {
+  %r = call i32 @llvm.arbitrary.fp.convert.i32.i8(
+      i8 %v, metadata !"signed", metadata !"spv.E4M3EXT", metadata !"none", i32 0)
+  ret i32 %r
+}
+
+define i8 @good_input_rounding(i32 %v) {
+  %r = call i8 @llvm.arbitrary.fp.convert.i8.i32(
+      i32 %v, metadata !"spv.E4M3EXT", metadata !"signed", metadata !"none", i32 0)
+  ret i8 %r
+}
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arsenm wrote:

Also test vector cases 

https://github.com/llvm/llvm-project/pull/164252