llvm-mirror/test/Transforms/Inline/alloca-bonus.ll
Nick Lewycky 7693b940b6 Support pointer comparisons against constants, when looking at the inline-cost
savings from a pointer argument becoming an alloca. Sometimes callees will even
compare a pointer to null and then branch to an otherwise unreachable block!
Detect these cases and compute the number of saved instructions, instead of
bailing out and reporting no savings.

llvm-svn: 148941
2012-01-25 08:27:40 +00:00

84 lines
1.9 KiB
LLVM

; RUN: opt -inline < %s -S -o - -inline-threshold=8 | FileCheck %s
declare void @llvm.lifetime.start(i64 %size, i8* nocapture %ptr)
@glbl = external global i32
define void @outer1() {
; CHECK: @outer1
; CHECK-NOT: call void @inner1
%ptr = alloca i32
call void @inner1(i32* %ptr)
ret void
}
define void @inner1(i32 *%ptr) {
%A = load i32* %ptr
store i32 0, i32* %ptr
%C = getelementptr i32* %ptr, i32 0
%D = getelementptr i32* %ptr, i32 1
%E = bitcast i32* %ptr to i8*
%F = select i1 false, i32* %ptr, i32* @glbl
call void @llvm.lifetime.start(i64 0, i8* %E)
ret void
}
define void @outer2() {
; CHECK: @outer2
; CHECK: call void @inner2
%ptr = alloca i32
call void @inner2(i32* %ptr)
ret void
}
; %D poisons this call, scalar-repl can't handle that instruction.
define void @inner2(i32 *%ptr) {
%A = load i32* %ptr
store i32 0, i32* %ptr
%C = getelementptr i32* %ptr, i32 0
%D = getelementptr i32* %ptr, i32 %A
%E = bitcast i32* %ptr to i8*
%F = select i1 false, i32* %ptr, i32* @glbl
call void @llvm.lifetime.start(i64 0, i8* %E)
ret void
}
define void @outer3() {
; CHECK: @outer3
; CHECK-NOT: call void @inner3
%ptr = alloca i32
call void @inner3(i32* %ptr, i1 undef)
ret void
}
define void @inner3(i32 *%ptr, i1 %x) {
%A = icmp eq i32* %ptr, null
%B = and i1 %x, %A
br i1 %A, label %bb.true, label %bb.false
bb.true:
; This block musn't be counted in the inline cost.
%t1 = load i32* %ptr
%t2 = add i32 %t1, 1
%t3 = add i32 %t2, 1
%t4 = add i32 %t3, 1
%t5 = add i32 %t4, 1
%t6 = add i32 %t5, 1
%t7 = add i32 %t6, 1
%t8 = add i32 %t7, 1
%t9 = add i32 %t8, 1
%t10 = add i32 %t9, 1
%t11 = add i32 %t10, 1
%t12 = add i32 %t11, 1
%t13 = add i32 %t12, 1
%t14 = add i32 %t13, 1
%t15 = add i32 %t14, 1
%t16 = add i32 %t15, 1
%t17 = add i32 %t16, 1
%t18 = add i32 %t17, 1
%t19 = add i32 %t18, 1
%t20 = add i32 %t19, 1
ret void
bb.false:
ret void
}