[ConstraintElimination] Extend test coverage.

This patch adds a lot of additional tests, focusing on loops and GEP arithmetic. Some of the tests expose existing problems, which will be fixed soon.
llvm · Feb 6, 2021 · 14da287 · 14da287
1 parent e6810ca
commit 14da287
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Showing 15 changed files with 2,813 additions and 7 deletions.
diff --git a/llvm/test/Transforms/ConstraintElimination/add-nuw.ll b/llvm/test/Transforms/ConstraintElimination/add-nuw.ll
@@ -335,5 +335,70 @@ if.end:                                           ; preds = %entry
 }
 
 
+define i1 @test_n_must_ule_1_due_to_nuw(i8 %n, i8 %i) {
+entry:
+  %sub.n.1 = add nuw i8 %n, -1
+  %add = add nuw i8 %i, %sub.n.1
+  %c.1 = icmp uge i8 %i, %add
+  br i1 %c.1, label %if.then, label %if.end
+
+if.then:                                          ; preds = %entry
+  %t = icmp ule i8 %n, 1
+  ret i1 %t
+
+if.end:                                           ; preds = %entry
+  %f = icmp ule i8 %n, 1
+  ret i1 %f
+}
+
+
+define i1 @test_n_unknown_missing_nuw(i8 %n, i8 %i) {
+entry:
+  %sub.n.1 = add i8 %n, -1
+  %add = add i8 %i, %sub.n.1
+  %c.1 = icmp uge i8 %i, %add
+  br i1 %c.1, label %if.then, label %if.end
+
+if.then:                                          ; preds = %entry
+  %t = icmp ule i8 %n, 1
+  ret i1 %t
+
+if.end:                                           ; preds = %entry
+  %f = icmp ule i8 %n, 1
+  ret i1 %f
+}
+
+define i1 @test_n_must_ule_2_due_to_nuw(i8 %n, i8 %i) {
+entry:
+  %sub.n.1 = add nuw i8 %n, -2
+  %add = add nuw i8 %i, %sub.n.1
+  %c.1 = icmp uge i8 %i, %add
+  br i1 %c.1, label %if.then, label %if.end
+
+if.then:                                          ; preds = %entry
+  %t = icmp ule i8 %n, 2
+  ret i1 %t
+
+if.end:                                           ; preds = %entry
+  %f = icmp ule i8 %n, 2
+  ret i1 %f
+}
+
+
+define i1 @test_n_unknown_missing_nuw2(i8 %n, i8 %i) {
+entry:
+  %sub.n.1 = add i8 %n, -2
+  %add = add i8 %i, %sub.n.1
+  %c.1 = icmp uge i8 %i, %add
+  br i1 %c.1, label %if.then, label %if.end
+
+if.then:                                          ; preds = %entry
+  %t = icmp ule i8 %n, 1
+  ret i1 %t
+
+if.end:                                           ; preds = %entry
+  %f = icmp ule i8 %n, 1
+  ret i1 %f
+}
+
 declare void @use(i1)
-declare void @llvm.trap()
diff --git a/llvm/test/Transforms/ConstraintElimination/add.ll b/llvm/test/Transforms/ConstraintElimination/add.ll
@@ -239,4 +239,3 @@ if.end:                                           ; preds = %entry
 
 
 declare void @use(i1)
-declare void @llvm.trap()
diff --git a/llvm/test/Transforms/ConstraintElimination/and.ll b/llvm/test/Transforms/ConstraintElimination/and.ll
@@ -135,3 +135,30 @@ exit:
 
   ret i32 20
 }
+
+define i4 @and_compare_undef(i16 %N, i16 %step) {
+; CHECK-LABEL: @and_compare_undef(
+; CHECK-NEXT:  step.check:
+; CHECK-NEXT:    [[STEP_POS:%.*]] = icmp uge i16 [[STEP:%.*]], 0
+; CHECK-NEXT:    [[B1:%.*]] = add i16 undef, -1
+; CHECK-NEXT:    [[STEP_ULT_N:%.*]] = icmp ult i16 [[B1]], [[N:%.*]]
+; CHECK-NEXT:    [[AND_STEP:%.*]] = and i1 [[STEP_POS]], [[STEP_ULT_N]]
+; CHECK-NEXT:    br i1 [[AND_STEP]], label [[PTR_CHECK:%.*]], label [[EXIT:%.*]]
+; CHECK:       ptr.check:
+; CHECK-NEXT:    br label [[EXIT]]
+; CHECK:       exit:
+; CHECK-NEXT:    ret i4 3
+;
+step.check:
+  %step.pos = icmp uge i16 %step, 0
+  %B1 = add i16 undef, -1
+  %step.ult.N = icmp ult i16 %B1, %N
+  %and.step = and i1 %step.pos, %step.ult.N
+  br i1 %and.step, label %ptr.check, label %exit
+
+ptr.check:
+  br label %exit
+
+exit:
+  ret i4 3
+}