[PATCH] D140885: llvm-reduce: Don't remove strictfp

[Matt Arsenault via Phabricator via llvm-commits]

arsenm created this revision.
arsenm added reviewers: jdoerfert, aeubanks, regehr, kpn, sepavloff.
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The verifier should fail if constrained intrinsics are used in
functions with strictfp, but that patch hasn't been pushed yet.

     

Ideally we would be able to analyze the function body to see if any
constrained intrinsics were used, but we seem to be missing a utility
function to check for any constrained ops.


https://reviews.llvm.org/D140885

Files:
  llvm/test/tools/llvm-reduce/remove-attributes-strictfp.ll
  llvm/tools/llvm-reduce/deltas/ReduceAttributes.cpp


Index: llvm/tools/llvm-reduce/deltas/ReduceAttributes.cpp
===================================================================
--- llvm/tools/llvm-reduce/deltas/ReduceAttributes.cpp
+++ llvm/tools/llvm-reduce/deltas/ReduceAttributes.cpp
@@ -128,6 +128,13 @@
 
         if (RemoveNoInline && Kind == Attribute::OptimizeNone)
           continue;
+
+        // TODO: Could only remove this if there are no constrained calls in the
+        // function.
+        if (Kind == Attribute::StrictFP) {
+          AttrsToPreserve.addAttribute(A);
+          continue;
+        }
       }
 
       if (O.shouldKeep())
Index: llvm/test/tools/llvm-reduce/remove-attributes-strictfp.ll
===================================================================
--- /dev/null
+++ llvm/test/tools/llvm-reduce/remove-attributes-strictfp.ll
@@ -0,0 +1,48 @@
+; RUN: llvm-reduce --abort-on-invalid-reduction --delta-passes=attributes --test FileCheck --test-arg %s --test-arg --input-file %s -o %t
+; RUN: FileCheck --check-prefixes=CHECK,RESULT %s < %t
+
+; Test that invalid reductions aren't produced on strictfp functions.
+
+; CHECK-LABEL: define float @strictfp_intrinsic(float %x, float %y)
+; RESULT-SAME: [[STRICTFP_ONLY:#[0-9]+]] {
+define float @strictfp_intrinsic(float %x, float %y) #0 {
+  %val = call float @llvm.experimental.constrained.fadd.f32(float %x, float %y, metadata !"round.tonearest", metadata !"fpexcept.strict")
+  ret float %val
+}
+
+; CHECK-LABEL: define float @strictfp_callsite(float %x, float %y)
+; RESULT-SAME: [[STRICTFP_ONLY]] {
+; RESULT: call float @extern.func(float %x, float %y) [[STRICTFP_ONLY]]
+define float @strictfp_callsite(float %x, float %y) #0 {
+  %val = call float @extern.func(float %x, float %y) #0
+  ret float %val
+}
+
+; CHECK-LABEL: define float @strictfp_declaration(float %x, float %y)
+; RESULT-SAME: [[STRICTFP_ONLY]] {
+define float @strictfp_declaration(float %x, float %y) #0 {
+  %val = call float @strict.extern.func(float %x, float %y)
+  ret float %val
+}
+
+; CHECK-LABEL: define float @strictfp_no_constrained_ops(float %x, float %y)
+; RESULT-SAME: [[STRICTFP_ONLY]] {
+define float @strictfp_no_constrained_ops(float %x, float %y) #0 {
+  %val = call float @llvm.copysign.f32(float %x, float %y)
+  ret float %val
+}
+
+; CHECK-LABEL: declare float @strict.extern.func(float, float)
+; RESULT-SAME: [[STRICTFP_ONLY]]{{$}}
+declare float @strict.extern.func(float, float) #0
+
+declare float @extern.func(float, float)
+
+declare float @llvm.copysign.f32(float, float) #1
+declare float @llvm.experimental.constrained.fadd.f32(float, float, metadata, metadata) #2
+
+; RESULT: attributes [[STRICTFP_ONLY]] = { strictfp }
+
+attributes #0 = { nounwind strictfp }
+attributes #1 = { nocallback nofree nosync nounwind speculatable willreturn memory(none) }
+attributes #2 = { nocallback nofree nosync nounwind willreturn memory(inaccessiblemem: readwrite) }


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