1 files changed, 73 insertions, 50 deletions
diff --git a/test/Transforms/Inline/inline_constprop.ll b/test/Transforms/Inline/inline_constprop.ll
index cc7aaac..dc35b60 100644
--- a/test/Transforms/Inline/inline_constprop.ll
+++ b/test/Transforms/Inline/inline_constprop.ll
@@ -1,4 +1,4 @@
-; RUN: opt < %s -inline -S | FileCheck %s
+; RUN: opt < %s -inline -inline-threshold=20 -S | FileCheck %s
 
 define internal i32 @callee1(i32 %A, i32 %B) {
   %C = sdiv i32 %A, %B
@@ -14,17 +14,18 @@ define i32 @caller1() {
 }
 
 define i32 @caller2() {
+; Check that we can constant-prop through instructions after inlining callee21
+; to get constants in the inlined callsite to callee22.
+; FIXME: Currently, the threshold is fixed at 20 because we don't perform
+; *recursive* cost analysis to realize that the nested call site will definitely
+; inline and be cheap. We should eventually do that and lower the threshold here
+; to 1.
+;
 ; CHECK: @caller2
 ; CHECK-NOT: call void @callee2
 ; CHECK: ret
 
-; We contrive to make this hard for *just* the inline pass to do in order to
-; simulate what can actually happen with large, complex functions getting
-; inlined.
-  %a = add i32 42, 0
-  %b = add i32 48, 0
-
-  %x = call i32 @callee21(i32 %a, i32 %b)
+  %x = call i32 @callee21(i32 42, i32 48)
   ret i32 %x
 }
 
@@ -41,49 +42,71 @@ define i32 @callee22(i32 %x) {
   br i1 %icmp, label %bb.true, label %bb.false
 bb.true:
   ; This block musn't be counted in the inline cost.
-  %ptr = call i8* @getptr()
-  load volatile i8* %ptr
-  load volatile i8* %ptr
-  load volatile i8* %ptr
-  load volatile i8* %ptr
-  load volatile i8* %ptr
-  load volatile i8* %ptr
-  load volatile i8* %ptr
-  load volatile i8* %ptr
-  load volatile i8* %ptr
-  load volatile i8* %ptr
-  load volatile i8* %ptr
-  load volatile i8* %ptr
-  load volatile i8* %ptr
-  load volatile i8* %ptr
-  load volatile i8* %ptr
-  load volatile i8* %ptr
-  load volatile i8* %ptr
-  load volatile i8* %ptr
-  load volatile i8* %ptr
-  load volatile i8* %ptr
-  load volatile i8* %ptr
-  load volatile i8* %ptr
-  load volatile i8* %ptr
-  load volatile i8* %ptr
-  load volatile i8* %ptr
-  load volatile i8* %ptr
-  load volatile i8* %ptr
-  load volatile i8* %ptr
-  load volatile i8* %ptr
-  load volatile i8* %ptr
-  load volatile i8* %ptr
-  load volatile i8* %ptr
-  load volatile i8* %ptr
-  load volatile i8* %ptr
-  load volatile i8* %ptr
-  load volatile i8* %ptr
-  load volatile i8* %ptr
-  load volatile i8* %ptr
-  load volatile i8* %ptr
-  load volatile i8* %ptr
+  %x1 = add i32 %x, 1
+  %x2 = add i32 %x1, 1
+  %x3 = add i32 %x2, 1
+  %x4 = add i32 %x3, 1
+  %x5 = add i32 %x4, 1
+  %x6 = add i32 %x5, 1
+  %x7 = add i32 %x6, 1
+  %x8 = add i32 %x7, 1
 
-  ret i32 %x
+  ret i32 %x8
 bb.false:
   ret i32 %x
 }
+
+define i32 @caller3() {
+; Check that even if the expensive path is hidden behind several basic blocks,
+; it doesn't count toward the inline cost when constant-prop proves those paths
+; dead.
+;
+; CHECK: @caller3
+; CHECK-NOT: call
+; CHECK: ret i32 6
+
+entry:
+  %x = call i32 @callee3(i32 42, i32 48)
+  ret i32 %x
+}
+
+define i32 @callee3(i32 %x, i32 %y) {
+  %sub = sub i32 %y, %x
+  %icmp = icmp ugt i32 %sub, 42
+  br i1 %icmp, label %bb.true, label %bb.false
+
+bb.true:
+  %icmp2 = icmp ult i32 %sub, 64
+  br i1 %icmp2, label %bb.true.true, label %bb.true.false
+
+bb.true.true:
+  ; This block musn't be counted in the inline cost.
+  %x1 = add i32 %x, 1
+  %x2 = add i32 %x1, 1
+  %x3 = add i32 %x2, 1
+  %x4 = add i32 %x3, 1
+  %x5 = add i32 %x4, 1
+  %x6 = add i32 %x5, 1
+  %x7 = add i32 %x6, 1
+  %x8 = add i32 %x7, 1
+  br label %bb.merge
+
+bb.true.false:
+  ; This block musn't be counted in the inline cost.
+  %y1 = add i32 %y, 1
+  %y2 = add i32 %y1, 1
+  %y3 = add i32 %y2, 1
+  %y4 = add i32 %y3, 1
+  %y5 = add i32 %y4, 1
+  %y6 = add i32 %y5, 1
+  %y7 = add i32 %y6, 1
+  %y8 = add i32 %y7, 1
+  br label %bb.merge
+
+bb.merge:
+  %result = phi i32 [ %x8, %bb.true.true ], [ %y8, %bb.true.false ]
+  ret i32 %result
+
+bb.false:
+  ret i32 %sub
+}