llvm-6502/test/Transforms/TailCallElim/accum_recursion.ll

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; RUN: opt < %s -tailcallelim -S | FileCheck %s
define i32 @test1_factorial(i32 %x) {
entry:
%tmp.1 = icmp sgt i32 %x, 0 ; <i1> [#uses=1]
br i1 %tmp.1, label %then, label %else
then: ; preds = %entry
%tmp.6 = add i32 %x, -1 ; <i32> [#uses=1]
%tmp.4 = call i32 @test1_factorial( i32 %tmp.6 ) ; <i32> [#uses=1]
%tmp.7 = mul i32 %tmp.4, %x ; <i32> [#uses=1]
ret i32 %tmp.7
else: ; preds = %entry
ret i32 1
}
; CHECK: define i32 @test1_factorial
; CHECK: phi i32
; CHECK-NOT: call i32
; CHECK: else:
; 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 ; <i1> [#uses=1]
br i1 %tmp.1, label %return, label %endif
endif: ; preds = %entry
%tmp.8 = add i32 %y, -1 ; <i32> [#uses=1]
%tmp.5 = call i32 @test2_mul( i32 %x, i32 %tmp.8 ) ; <i32> [#uses=1]
%tmp.9 = add i32 %tmp.5, %x ; <i32> [#uses=1]
ret i32 %tmp.9
return: ; preds = %entry
ret i32 %x
}
; CHECK: define i32 @test2_mul
; CHECK: phi i32
; CHECK-NOT: call i32
; CHECK: return: