mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-12-12 13:30:51 +00:00
e14fb07357
This adds another heuristic to BPI, similar to the existing heuristic that considers (x == 0) unlikely to be true. As suggested in the PACT'98 paper by Deitrich, Cheng, and Hwu, -1 is often used to indicate an invalid index, and equality comparisons with -1 are also unlikely to succeed. Local experimentation supports this hypothesis: This yields a 1-2% speedup in the test-suite sqlite benchmark on the PPC A2 core, with no significant regressions. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193855 91177308-0d34-0410-b5e6-96231b3b80d8
215 lines
5.6 KiB
LLVM
215 lines
5.6 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}
|
|
|
|
define i32 @test4(i32 %x) nounwind uwtable readnone ssp {
|
|
; CHECK: Printing analysis {{.*}} for function 'test4'
|
|
entry:
|
|
%conv = sext i32 %x to i64
|
|
switch i64 %conv, label %return [
|
|
i64 0, label %sw.bb
|
|
i64 1, label %sw.bb
|
|
i64 2, label %sw.bb
|
|
i64 5, label %sw.bb1
|
|
], !prof !2
|
|
; CHECK: edge entry -> return probability is 7 / 85
|
|
; CHECK: edge entry -> sw.bb probability is 14 / 85
|
|
; CHECK: edge entry -> sw.bb1 probability is 64 / 85
|
|
|
|
sw.bb:
|
|
br label %return
|
|
|
|
sw.bb1:
|
|
br label %return
|
|
|
|
return:
|
|
%retval.0 = phi i32 [ 5, %sw.bb1 ], [ 1, %sw.bb ], [ 0, %entry ]
|
|
ret i32 %retval.0
|
|
}
|
|
|
|
!2 = metadata !{metadata !"branch_weights", i32 7, i32 6, i32 4, i32 4, i32 64}
|
|
|
|
declare void @coldfunc() cold
|
|
|
|
define i32 @test5(i32 %a, i32 %b, i1 %flag) {
|
|
; CHECK: Printing analysis {{.*}} for function 'test5'
|
|
entry:
|
|
br i1 %flag, label %then, label %else
|
|
; CHECK: edge entry -> then probability is 4 / 68
|
|
; CHECK: edge entry -> else probability is 64 / 68
|
|
|
|
then:
|
|
call void @coldfunc()
|
|
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
|
|
}
|
|
|
|
declare i32 @regular_function(i32 %i)
|
|
|
|
define i32 @test_cold_call_sites(i32* %a) {
|
|
; Test that edges to blocks post-dominated by cold call sites
|
|
; are marked as not expected to be taken.
|
|
; TODO(dnovillo) The calls to regular_function should not be merged, but
|
|
; they are currently being merged. Convert this into a code generation test
|
|
; after that is fixed.
|
|
|
|
; CHECK: Printing analysis {{.*}} for function 'test_cold_call_sites'
|
|
; CHECK: edge entry -> then probability is 4 / 68 = 5.88235%
|
|
; CHECK: edge entry -> else probability is 64 / 68 = 94.1176% [HOT edge]
|
|
|
|
entry:
|
|
%gep1 = getelementptr i32* %a, i32 1
|
|
%val1 = load i32* %gep1
|
|
%cond1 = icmp ugt i32 %val1, 1
|
|
br i1 %cond1, label %then, label %else
|
|
|
|
then:
|
|
; This function is not declared cold, but this call site is.
|
|
%val4 = call i32 @regular_function(i32 %val1) cold
|
|
br label %exit
|
|
|
|
else:
|
|
%gep2 = getelementptr i32* %a, i32 2
|
|
%val2 = load i32* %gep2
|
|
%val3 = call i32 @regular_function(i32 %val2)
|
|
br label %exit
|
|
|
|
exit:
|
|
%ret = phi i32 [ %val4, %then ], [ %val3, %else ]
|
|
ret i32 %ret
|
|
}
|
|
|
|
define i32 @zero1(i32 %i, i32 %a, i32 %b) {
|
|
; CHECK: Printing analysis {{.*}} for function 'zero1'
|
|
entry:
|
|
%cond = icmp eq i32 %i, 0
|
|
br i1 %cond, label %then, label %else
|
|
; CHECK: edge entry -> then probability is 12 / 32
|
|
; CHECK: edge entry -> else probability is 20 / 32
|
|
|
|
then:
|
|
br label %exit
|
|
|
|
else:
|
|
br label %exit
|
|
|
|
exit:
|
|
%result = phi i32 [ %a, %then ], [ %b, %else ]
|
|
ret i32 %result
|
|
}
|
|
|
|
define i32 @zero2(i32 %i, i32 %a, i32 %b) {
|
|
; CHECK: Printing analysis {{.*}} for function 'zero2'
|
|
entry:
|
|
%cond = icmp ne i32 %i, -1
|
|
br i1 %cond, label %then, label %else
|
|
; CHECK: edge entry -> then probability is 20 / 32
|
|
; CHECK: edge entry -> else probability is 12 / 32
|
|
|
|
then:
|
|
br label %exit
|
|
|
|
else:
|
|
br label %exit
|
|
|
|
exit:
|
|
%result = phi i32 [ %a, %then ], [ %b, %else ]
|
|
ret i32 %result
|
|
}
|
|
|