Constant propagation after hiting llvm.assume

[oota-llvm.git] / test / Transforms / GVN / assume-equal.ll

diff --git a/test/Transforms/GVN/assume-equal.ll b/test/Transforms/GVN/assume-equal.ll
new file mode 100644 (file)
index 0000000..c1665bd
--- /dev/null
+++ b/test/Transforms/GVN/assume-equal.ll
@@ -0,0 +1,122 @@
+; RUN: opt < %s -gvn -S | FileCheck %s
+
+%struct.A = type { i32 (...)** }
+@_ZTV1A = available_externally unnamed_addr constant [4 x i8*] [i8* null, i8* bitcast (i8** @_ZTI1A to i8*), i8* bitcast (i32 (%struct.A*)* @_ZN1A3fooEv to i8*), i8* bitcast (i32 (%struct.A*)* @_ZN1A3barEv to i8*)], align 8
+@_ZTI1A = external constant i8*
+
+; Checks if indirect calls can be replaced with direct
+; assuming that %vtable == @_ZTV1A (with alignment).
+; Checking const propagation across other BBs
+; CHECK-LABEL: define void @_Z1gb(
+
+define void @_Z1gb(i1 zeroext %p) {
+entry:
+  %call = tail call noalias i8* @_Znwm(i64 8) #4
+  %0 = bitcast i8* %call to %struct.A*
+  tail call void @_ZN1AC1Ev(%struct.A* %0) #1
+  %1 = bitcast i8* %call to i8***
+  %vtable = load i8**, i8*** %1, align 8
+  %cmp.vtables = icmp eq i8** %vtable, getelementptr inbounds ([4 x i8*], [4 x i8*]* @_ZTV1A, i64 0, i64 2)
+  tail call void @llvm.assume(i1 %cmp.vtables)
+  br i1 %p, label %if.then, label %if.else
+
+if.then:                                          ; preds = %entry
+  %vtable1.cast = bitcast i8** %vtable to i32 (%struct.A*)**
+  %2 = load i32 (%struct.A*)*, i32 (%struct.A*)** %vtable1.cast, align 8
+  
+  ; CHECK: call i32 @_ZN1A3fooEv(
+  %call2 = tail call i32 %2(%struct.A* %0) #1
+  
+  br label %if.end
+
+if.else:                                          ; preds = %entry
+  %vfn47 = getelementptr inbounds i8*, i8** %vtable, i64 1
+  %vfn4 = bitcast i8** %vfn47 to i32 (%struct.A*)**
+  
+  ; CHECK: call i32 @_ZN1A3barEv(
+  %3 = load i32 (%struct.A*)*, i32 (%struct.A*)** %vfn4, align 8
+  
+  %call5 = tail call i32 %3(%struct.A* %0) #1
+  br label %if.end
+
+if.end:                                           ; preds = %if.else, %if.then
+  ret void
+}
+
+; Checking const propagation in the same BB
+; CHECK-LABEL: define i32 @main()
+
+define i32 @main() {
+entry:
+  %call = tail call noalias i8* @_Znwm(i64 8) 
+  %0 = bitcast i8* %call to %struct.A*
+  tail call void @_ZN1AC1Ev(%struct.A* %0) 
+  %1 = bitcast i8* %call to i8***
+  %vtable = load i8**, i8*** %1, align 8
+  %cmp.vtables = icmp eq i8** %vtable, getelementptr inbounds ([4 x i8*], [4 x i8*]* @_ZTV1A, i64 0, i64 2)
+  tail call void @llvm.assume(i1 %cmp.vtables)
+  %vtable1.cast = bitcast i8** %vtable to i32 (%struct.A*)**
+  
+  ; CHECK: call i32 @_ZN1A3fooEv(
+  %2 = load i32 (%struct.A*)*, i32 (%struct.A*)** %vtable1.cast, align 8
+  
+  %call2 = tail call i32 %2(%struct.A* %0)
+  ret i32 0
+}
+
+; This tests checks const propatation with fcmp instruction.
+; CHECK-LABEL: define float @_Z1gf(float %p)
+
+define float @_Z1gf(float %p) {
+entry:
+  %p.addr = alloca float, align 4
+  %f = alloca float, align 4
+  store float %p, float* %p.addr, align 4
+  
+  store float 3.000000e+00, float* %f, align 4
+  %0 = load float, float* %p.addr, align 4
+  %1 = load float, float* %f, align 4
+  %cmp = fcmp oeq float %1, %0 ; note const on lhs
+  call void @llvm.assume(i1 %cmp)
+  
+  ; CHECK: ret float 3.000000e+00
+  ret float %0
+}
+
+; CHECK-LABEL: define float @_Z1hf(float %p)
+
+define float @_Z1hf(float %p) {
+entry:
+  %p.addr = alloca float, align 4
+  store float %p, float* %p.addr, align 4
+  
+  %0 = load float, float* %p.addr, align 4
+  %cmp = fcmp nnan ueq float %0, 3.000000e+00
+  call void @llvm.assume(i1 %cmp)
+  
+  ; CHECK: ret float 3.000000e+00
+  ret float %0
+}
+
+; CHECK-LABEL: define float @_Z1if(float %p)
+
+
+define float @_Z1if(float %p) {
+entry:
+  %p.addr = alloca float, align 4
+  store float %p, float* %p.addr, align 4
+  
+  %0 = load float, float* %p.addr, align 4
+  %cmp = fcmp ueq float %0, 3.000000e+00 ; no nnan flag - can't propagate
+  call void @llvm.assume(i1 %cmp)
+  
+  ; CHECK-NOT: ret float 3.000000e+00
+  ret float %0
+}
+
+declare noalias i8* @_Znwm(i64)
+declare void @_ZN1AC1Ev(%struct.A*)
+declare void @llvm.assume(i1)
+declare i32 @_ZN1A3fooEv(%struct.A*)
+declare i32 @_ZN1A3barEv(%struct.A*)
+