llvm-mirror/test/Analysis/BranchProbabilityInfo/basic.ll
Chandler Carruth 151d4fc273 Teach the BranchProbabilityInfo pass to print its results, and use that
to bring it under direct test instead of merely indirectly testing it in
the BlockFrequencyInfo pass.

The next step is to start adding tests for the various heuristics
employed, and to start fixing those heuristics once they're under test.

llvm-svn: 142778
2011-10-23 21:21:50 +00:00

91 lines
2.5 KiB
LLVM

; RUN: opt < %s -analyze -branch-prob | FileCheck %s
define i32 @test1(i32 %i, i32* %a) {
; CHECK: Printing analysis {{.*}} for function 'test1'
entry:
br label %body
; CHECK: edge entry -> body probability is 16 / 16 = 100%
body:
%iv = phi i32 [ 0, %entry ], [ %next, %body ]
%base = phi i32 [ 0, %entry ], [ %sum, %body ]
%arrayidx = getelementptr inbounds i32* %a, i32 %iv
%0 = load i32* %arrayidx
%sum = add nsw i32 %0, %base
%next = add i32 %iv, 1
%exitcond = icmp eq i32 %next, %i
br i1 %exitcond, label %exit, label %body
; CHECK: edge body -> exit probability is 4 / 128
; CHECK: edge body -> body probability is 124 / 128
exit:
ret i32 %sum
}
define i32 @test2(i32 %i, i32 %a, i32 %b) {
; CHECK: Printing analysis {{.*}} for function 'test2'
entry:
%cond = icmp ult i32 %i, 42
br i1 %cond, label %then, label %else, !prof !0
; CHECK: edge entry -> then probability is 64 / 68
; CHECK: edge entry -> else probability is 4 / 68
then:
br label %exit
; CHECK: edge then -> exit probability is 16 / 16 = 100%
else:
br label %exit
; CHECK: edge else -> exit probability is 16 / 16 = 100%
exit:
%result = phi i32 [ %a, %then ], [ %b, %else ]
ret i32 %result
}
!0 = metadata !{metadata !"branch_weights", i32 64, i32 4}
define i32 @test3(i32 %i, i32 %a, i32 %b, i32 %c, i32 %d, i32 %e) {
; CHECK: Printing analysis {{.*}} for function 'test3'
entry:
switch i32 %i, label %case_a [ i32 1, label %case_b
i32 2, label %case_c
i32 3, label %case_d
i32 4, label %case_e ], !prof !1
; CHECK: edge entry -> case_a probability is 4 / 80
; CHECK: edge entry -> case_b probability is 4 / 80
; CHECK: edge entry -> case_c probability is 64 / 80
; CHECK: edge entry -> case_d probability is 4 / 80
; CHECK: edge entry -> case_e probability is 4 / 80
case_a:
br label %exit
; CHECK: edge case_a -> exit probability is 16 / 16 = 100%
case_b:
br label %exit
; CHECK: edge case_b -> exit probability is 16 / 16 = 100%
case_c:
br label %exit
; CHECK: edge case_c -> exit probability is 16 / 16 = 100%
case_d:
br label %exit
; CHECK: edge case_d -> exit probability is 16 / 16 = 100%
case_e:
br label %exit
; CHECK: edge case_e -> exit probability is 16 / 16 = 100%
exit:
%result = phi i32 [ %a, %case_a ],
[ %b, %case_b ],
[ %c, %case_c ],
[ %d, %case_d ],
[ %e, %case_e ]
ret i32 %result
}
!1 = metadata !{metadata !"branch_weights", i32 4, i32 4, i32 64, i32 4, i32 4}