1
0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-11-22 18:54:02 +01:00
llvm-mirror/test/Transforms/TailCallElim/accum_recursion.ll
Layton Kifer d2b5e40119 [TRE] Allow accumulator elimination when base case returns non-constant
Remove the requirement, that when performing accumulator elimination,
all other cases must return the same dynamic constant. We can do this by
initializing the accumulator with the identity value of the accumulation
operation, and inserting an additional operation before any return.

Differential Revision: https://reviews.llvm.org/D80844
2020-06-04 10:34:42 -07:00

225 lines
6.5 KiB
LLVM

; RUN: opt < %s -tailcallelim -verify-dom-info -S | FileCheck %s
; RUN: opt < %s -passes=tailcallelim -verify-dom-info -S | FileCheck %s
define i32 @test1_factorial(i32 %x) {
entry:
%tmp.1 = icmp sgt i32 %x, 0
br i1 %tmp.1, label %then, label %else
then:
%tmp.6 = add i32 %x, -1
%recurse = call i32 @test1_factorial( i32 %tmp.6 )
%accumulate = mul i32 %recurse, %x
ret i32 %accumulate
else:
ret i32 1
}
; CHECK-LABEL: define i32 @test1_factorial(
; CHECK: tailrecurse:
; CHECK: %accumulator.tr = phi i32 [ 1, %entry ], [ %accumulate, %then ]
; CHECK: then:
; CHECK-NOT: %recurse
; CHECK: %accumulate = mul i32 %accumulator.tr, %x.tr
; CHECK: else:
; CHECK: %accumulator.ret.tr = mul i32 %accumulator.tr, 1
; CHECK: ret i32 %accumulator.ret.tr
; This is a more aggressive form of accumulator recursion insertion, which
; requires noticing that X doesn't change as we perform the tailcall.
define i32 @test2_mul(i32 %x, i32 %y) {
entry:
%tmp.1 = icmp eq i32 %y, 0
br i1 %tmp.1, label %return, label %endif
endif:
%tmp.8 = add i32 %y, -1
%recurse = call i32 @test2_mul( i32 %x, i32 %tmp.8 )
%accumulate = add i32 %recurse, %x
ret i32 %accumulate
return:
ret i32 %x
}
; CHECK-LABEL: define i32 @test2_mul(
; CHECK: tailrecurse:
; CHECK: %accumulator.tr = phi i32 [ 0, %entry ], [ %accumulate, %endif ]
; CHECK: endif:
; CHECK-NOT: %recurse
; CHECK: %accumulate = add i32 %accumulator.tr, %x
; CHECK: return:
; CHECK: %accumulator.ret.tr = add i32 %accumulator.tr, %x
; CHECK: ret i32 %accumulator.ret.tr
define i64 @test3_fib(i64 %n) nounwind readnone {
entry:
switch i64 %n, label %bb1 [
i64 0, label %bb2
i64 1, label %bb2
]
bb1:
%0 = add i64 %n, -1
%recurse1 = tail call i64 @test3_fib(i64 %0) nounwind
%1 = add i64 %n, -2
%recurse2 = tail call i64 @test3_fib(i64 %1) nounwind
%accumulate = add nsw i64 %recurse2, %recurse1
ret i64 %accumulate
bb2:
ret i64 %n
}
; CHECK-LABEL: define i64 @test3_fib(
; CHECK: tailrecurse:
; CHECK: %accumulator.tr = phi i64 [ 0, %entry ], [ %accumulate, %bb1 ]
; CHECK: bb1:
; CHECK-NOT: %recurse2
; CHECK: %accumulate = add nsw i64 %accumulator.tr, %recurse1
; CHECK: bb2:
; CHECK: %accumulator.ret.tr = add nsw i64 %accumulator.tr, %n.tr
; CHECK: ret i64 %accumulator.ret.tr
define i32 @test4_base_case_call() local_unnamed_addr {
entry:
%base = call i32 @test4_helper()
switch i32 %base, label %sw.default [
i32 1, label %cleanup
i32 5, label %cleanup
i32 7, label %cleanup
]
sw.default:
%recurse = call i32 @test4_base_case_call()
%accumulate = add nsw i32 %recurse, 1
br label %cleanup
cleanup:
%retval.0 = phi i32 [ %accumulate, %sw.default ], [ %base, %entry ], [ %base, %entry ], [ %base, %entry ]
ret i32 %retval.0
}
declare i32 @test4_helper()
; CHECK-LABEL: define i32 @test4_base_case_call(
; CHECK: tailrecurse:
; CHECK: %accumulator.tr = phi i32 [ 0, %entry ], [ %accumulate, %sw.default ]
; CHECK: sw.default:
; CHECK-NOT: %recurse
; CHECK: %accumulate = add nsw i32 %accumulator.tr, 1
; CHECK: cleanup:
; CHECK: %accumulator.ret.tr = add nsw i32 %accumulator.tr, %base
; CHECK: ret i32 %accumulator.ret.tr
define i32 @test5_base_case_load(i32* nocapture %A, i32 %n) local_unnamed_addr {
entry:
%cmp = icmp eq i32 %n, 0
br i1 %cmp, label %if.then, label %if.end
if.then:
%base = load i32, i32* %A, align 4
ret i32 %base
if.end:
%idxprom = zext i32 %n to i64
%arrayidx1 = getelementptr inbounds i32, i32* %A, i64 %idxprom
%load = load i32, i32* %arrayidx1, align 4
%sub = add i32 %n, -1
%recurse = tail call i32 @test5_base_case_load(i32* %A, i32 %sub)
%accumulate = add i32 %recurse, %load
ret i32 %accumulate
}
; CHECK-LABEL: define i32 @test5_base_case_load(
; CHECK: tailrecurse:
; CHECK: %accumulator.tr = phi i32 [ 0, %entry ], [ %accumulate, %if.end ]
; CHECK: if.then:
; CHECK: %accumulator.ret.tr = add i32 %accumulator.tr, %base
; CHECK: ret i32 %accumulator.ret.tr
; CHECK: if.end:
; CHECK-NOT: %recurse
; CHECK: %accumulate = add i32 %accumulator.tr, %load
define i32 @test6_multiple_returns(i32 %x, i32 %y) local_unnamed_addr {
entry:
switch i32 %x, label %default [
i32 0, label %case0
i32 99, label %case99
]
case0:
%helper = call i32 @test6_helper()
ret i32 %helper
case99:
%sub1 = add i32 %x, -1
%recurse1 = call i32 @test6_multiple_returns(i32 %sub1, i32 %y)
ret i32 18
default:
%sub2 = add i32 %x, -1
%recurse2 = call i32 @test6_multiple_returns(i32 %sub2, i32 %y)
%accumulate = add i32 %recurse2, %y
ret i32 %accumulate
}
declare i32 @test6_helper()
; CHECK-LABEL: define i32 @test6_multiple_returns(
; CHECK: tailrecurse:
; CHECK: %accumulator.tr = phi i32 [ %accumulator.tr, %case99 ], [ 0, %entry ], [ %accumulate, %default ]
; CHECK: %ret.tr = phi i32 [ undef, %entry ], [ %current.ret.tr, %case99 ], [ %ret.tr, %default ]
; CHECK: %ret.known.tr = phi i1 [ false, %entry ], [ true, %case99 ], [ %ret.known.tr, %default ]
; CHECK: case0:
; CHECK: %accumulator.ret.tr2 = add i32 %accumulator.tr, %helper
; CHECK: %current.ret.tr1 = select i1 %ret.known.tr, i32 %ret.tr, i32 %accumulator.ret.tr2
; CHECK: case99:
; CHECK-NOT: %recurse
; CHECK: %accumulator.ret.tr = add i32 %accumulator.tr, 18
; CHECK: %current.ret.tr = select i1 %ret.known.tr, i32 %ret.tr, i32 %accumulator.ret.tr
; CHECK: default:
; CHECK-NOT: %recurse
; CHECK: %accumulate = add i32 %accumulator.tr, %y
; It is only safe to transform one accumulator per function, make sure we don't
; try to remove more.
define i32 @test7_multiple_accumulators(i32 %a) local_unnamed_addr {
entry:
%tobool = icmp eq i32 %a, 0
br i1 %tobool, label %return, label %if.end
if.end:
%and = and i32 %a, 1
%tobool1 = icmp eq i32 %and, 0
%sub = add nsw i32 %a, -1
br i1 %tobool1, label %if.end3, label %if.then2
if.then2:
%recurse1 = tail call i32 @test7_multiple_accumulators(i32 %sub)
%accumulate1 = add nsw i32 %recurse1, 1
br label %return
if.end3:
%recurse2 = tail call i32 @test7_multiple_accumulators(i32 %sub)
%accumulate2 = mul nsw i32 %recurse2, 2
br label %return
return:
%retval.0 = phi i32 [ %accumulate1, %if.then2 ], [ %accumulate2, %if.end3 ], [ 0, %entry ]
ret i32 %retval.0
}
; CHECK-LABEL: define i32 @test7_multiple_accumulators(
; CHECK: tailrecurse:
; CHECK: %accumulator.tr = phi i32 [ 0, %entry ], [ %accumulate1, %if.then2 ]
; CHECK: if.then2:
; CHECK-NOT: %recurse1
; CHECK: %accumulate1 = add nsw i32 %accumulator.tr, 1
; CHECK: if.end3:
; CHECK: %recurse2
; CHECK: %accumulator.ret.tr = add nsw i32 %accumulator.tr, %accumulate2
; CHECK: ret i32 %accumulator.ret.tr
; CHECK: return:
; CHECK: %accumulator.ret.tr1 = add nsw i32 %accumulator.tr, 0
; CHECK: ret i32 %accumulator.ret.tr1