[SystemZ][FPEnv] Back-end support for STRICT_[SU]INT_TO_FP

As of b1d8576 there is middle-end support for STRICT_[SU]INT_TO_FP,
so this patch adds SystemZ back-end support as well.

The patch is SystemZ target specific except for adding SD patterns
strict_[su]int_to_fp and any_[su]int_to_fp to TargetSelectionDAG.td
as usual.

1 files changed, 47 insertions, 0 deletions

diff --git a/llvm/test/CodeGen/SystemZ/fp-strict-conv-08.ll b/llvm/test/CodeGen/SystemZ/fp-strict-conv-08.ll
new file mode 100644
index 00000000000..a151c15e34d
--- /dev/null
+++ b/llvm/test/CodeGen/SystemZ/fp-strict-conv-08.ll
@@ -0,0 +1,47 @@
+; Test strict conversions of unsigned i64s to floating-point values (z10 only).
+;
+; RUN: llc < %s -mtriple=s390x-linux-gnu -mcpu=z10 | FileCheck %s
+
+declare float @llvm.experimental.constrained.uitofp.f32.i64(i64, metadata, metadata)
+declare double @llvm.experimental.constrained.uitofp.f64.i64(i64, metadata, metadata)
+declare fp128 @llvm.experimental.constrained.uitofp.f128.i64(i64, metadata, metadata)
+
+; Test i64->f32.  There's no native support for unsigned i64-to-fp conversions,
+; but we should be able to implement them using signed i64-to-fp conversions.
+define float @f1(i64 %i) #0 {
+; CHECK-LABEL: f1:
+; CHECK: cegbr
+; CHECK: aebr
+; CHECK: br %r14
+  %conv = call float @llvm.experimental.constrained.uitofp.f32.i64(i64 %i,
+                                               metadata !"round.dynamic",
+                                               metadata !"fpexcept.strict") #0
+  ret float %conv
+}
+
+; Test i64->f64.
+define double @f2(i64 %i) #0 {
+; CHECK-LABEL: f2:
+; CHECK: ldgr
+; CHECK: adbr
+; CHECK: br %r14
+  %conv = call double @llvm.experimental.constrained.uitofp.f64.i64(i64 %i,
+                                               metadata !"round.dynamic",
+                                               metadata !"fpexcept.strict") #0
+  ret double %conv
+}
+
+; Test i64->f128.
+define void @f3(i64 %i, fp128 *%dst) #0 {
+; CHECK-LABEL: f3:
+; CHECK: cxgbr
+; CHECK: axbr
+; CHECK: br %r14
+  %conv = call fp128 @llvm.experimental.constrained.uitofp.f128.i64(i64 %i,
+                                               metadata !"round.dynamic",
+                                               metadata !"fpexcept.strict") #0
+  store fp128 %conv, fp128 *%dst
+  ret void
+}
+
+attributes #0 = { strictfp }