llvm-6502/test/CodeGen/X86/lsr-reuse.ll
2010-03-18 06:55:42 +00:00

443 lines
14 KiB
LLVM

; RUN: llc < %s -march=x86-64 -O3 -asm-verbose=false | FileCheck %s
target datalayout = "e-p:64:64:64"
target triple = "x86_64-unknown-unknown"
; Full strength reduction reduces register pressure from 5 to 4 here.
; Instruction selection should use the FLAGS value from the dec for
; the branch. Scheduling should push the adds upwards.
; CHECK: full_me_0:
; CHECK: movsd (%rsi), %xmm0
; CHECK: mulsd (%rdx), %xmm0
; CHECK: movsd %xmm0, (%rdi)
; CHECK: addq $8, %rsi
; CHECK: addq $8, %rdx
; CHECK: addq $8, %rdi
; CHECK: decq %rcx
; CHECK: jne
define void @full_me_0(double* nocapture %A, double* nocapture %B, double* nocapture %C, i64 %n) nounwind {
entry:
%t0 = icmp sgt i64 %n, 0
br i1 %t0, label %loop, label %return
loop:
%i = phi i64 [ %i.next, %loop ], [ 0, %entry ]
%Ai = getelementptr inbounds double* %A, i64 %i
%Bi = getelementptr inbounds double* %B, i64 %i
%Ci = getelementptr inbounds double* %C, i64 %i
%t1 = load double* %Bi
%t2 = load double* %Ci
%m = fmul double %t1, %t2
store double %m, double* %Ai
%i.next = add nsw i64 %i, 1
%exitcond = icmp eq i64 %i.next, %n
br i1 %exitcond, label %return, label %loop
return:
ret void
}
; Mostly-full strength reduction means we do full strength reduction on all
; except for the offsets.
;
; Given a choice between constant offsets -2048 and 2048, choose the negative
; value, because at boundary conditions it has a smaller encoding.
; TODO: That's an over-general heuristic. It would be better for the target
; to indicate what the encoding cost would be. Then using a 2048 offset
; would be better on x86-64, since the start value would be 0 instead of
; 2048.
; CHECK: mostly_full_me_0:
; CHECK: movsd -2048(%rsi), %xmm0
; CHECK: mulsd -2048(%rdx), %xmm0
; CHECK: movsd %xmm0, -2048(%rdi)
; CHECK: movsd (%rsi), %xmm0
; CHECK: divsd (%rdx), %xmm0
; CHECK: movsd %xmm0, (%rdi)
; CHECK: addq $8, %rsi
; CHECK: addq $8, %rdx
; CHECK: addq $8, %rdi
; CHECK: decq %rcx
; CHECK: jne
define void @mostly_full_me_0(double* nocapture %A, double* nocapture %B, double* nocapture %C, i64 %n) nounwind {
entry:
%t0 = icmp sgt i64 %n, 0
br i1 %t0, label %loop, label %return
loop:
%i = phi i64 [ %i.next, %loop ], [ 0, %entry ]
%Ai = getelementptr inbounds double* %A, i64 %i
%Bi = getelementptr inbounds double* %B, i64 %i
%Ci = getelementptr inbounds double* %C, i64 %i
%t1 = load double* %Bi
%t2 = load double* %Ci
%m = fmul double %t1, %t2
store double %m, double* %Ai
%j = add i64 %i, 256
%Aj = getelementptr inbounds double* %A, i64 %j
%Bj = getelementptr inbounds double* %B, i64 %j
%Cj = getelementptr inbounds double* %C, i64 %j
%t3 = load double* %Bj
%t4 = load double* %Cj
%o = fdiv double %t3, %t4
store double %o, double* %Aj
%i.next = add nsw i64 %i, 1
%exitcond = icmp eq i64 %i.next, %n
br i1 %exitcond, label %return, label %loop
return:
ret void
}
; A minor variation on mostly_full_me_0.
; Prefer to start the indvar at 0.
; CHECK: mostly_full_me_1:
; CHECK: movsd (%rsi), %xmm0
; CHECK: mulsd (%rdx), %xmm0
; CHECK: movsd %xmm0, (%rdi)
; CHECK: movsd -2048(%rsi), %xmm0
; CHECK: divsd -2048(%rdx), %xmm0
; CHECK: movsd %xmm0, -2048(%rdi)
; CHECK: addq $8, %rsi
; CHECK: addq $8, %rdx
; CHECK: addq $8, %rdi
; CHECK: decq %rcx
; CHECK: jne
define void @mostly_full_me_1(double* nocapture %A, double* nocapture %B, double* nocapture %C, i64 %n) nounwind {
entry:
%t0 = icmp sgt i64 %n, 0
br i1 %t0, label %loop, label %return
loop:
%i = phi i64 [ %i.next, %loop ], [ 0, %entry ]
%Ai = getelementptr inbounds double* %A, i64 %i
%Bi = getelementptr inbounds double* %B, i64 %i
%Ci = getelementptr inbounds double* %C, i64 %i
%t1 = load double* %Bi
%t2 = load double* %Ci
%m = fmul double %t1, %t2
store double %m, double* %Ai
%j = sub i64 %i, 256
%Aj = getelementptr inbounds double* %A, i64 %j
%Bj = getelementptr inbounds double* %B, i64 %j
%Cj = getelementptr inbounds double* %C, i64 %j
%t3 = load double* %Bj
%t4 = load double* %Cj
%o = fdiv double %t3, %t4
store double %o, double* %Aj
%i.next = add nsw i64 %i, 1
%exitcond = icmp eq i64 %i.next, %n
br i1 %exitcond, label %return, label %loop
return:
ret void
}
; A slightly less minor variation on mostly_full_me_0.
; CHECK: mostly_full_me_2:
; CHECK: movsd (%rsi), %xmm0
; CHECK: mulsd (%rdx), %xmm0
; CHECK: movsd %xmm0, (%rdi)
; CHECK: movsd -4096(%rsi), %xmm0
; CHECK: divsd -4096(%rdx), %xmm0
; CHECK: movsd %xmm0, -4096(%rdi)
; CHECK: addq $8, %rsi
; CHECK: addq $8, %rdx
; CHECK: addq $8, %rdi
; CHECK: decq %rcx
; CHECK: jne
define void @mostly_full_me_2(double* nocapture %A, double* nocapture %B, double* nocapture %C, i64 %n) nounwind {
entry:
%t0 = icmp sgt i64 %n, 0
br i1 %t0, label %loop, label %return
loop:
%i = phi i64 [ %i.next, %loop ], [ 0, %entry ]
%k = add i64 %i, 256
%Ak = getelementptr inbounds double* %A, i64 %k
%Bk = getelementptr inbounds double* %B, i64 %k
%Ck = getelementptr inbounds double* %C, i64 %k
%t1 = load double* %Bk
%t2 = load double* %Ck
%m = fmul double %t1, %t2
store double %m, double* %Ak
%j = sub i64 %i, 256
%Aj = getelementptr inbounds double* %A, i64 %j
%Bj = getelementptr inbounds double* %B, i64 %j
%Cj = getelementptr inbounds double* %C, i64 %j
%t3 = load double* %Bj
%t4 = load double* %Cj
%o = fdiv double %t3, %t4
store double %o, double* %Aj
%i.next = add nsw i64 %i, 1
%exitcond = icmp eq i64 %i.next, %n
br i1 %exitcond, label %return, label %loop
return:
ret void
}
; In this test, the counting IV exit value is used, so full strength reduction
; would not reduce register pressure. IndVarSimplify ought to simplify such
; cases away, but it's useful here to verify that LSR's register pressure
; heuristics are working as expected.
; CHECK: count_me_0:
; CHECK: movsd (%rsi,%rax,8), %xmm0
; CHECK: mulsd (%rdx,%rax,8), %xmm0
; CHECK: movsd %xmm0, (%rdi,%rax,8)
; CHECK: incq %rax
; CHECK: cmpq %rax, %rcx
; CHECK: jne
define i64 @count_me_0(double* nocapture %A, double* nocapture %B, double* nocapture %C, i64 %n) nounwind {
entry:
%t0 = icmp sgt i64 %n, 0
br i1 %t0, label %loop, label %return
loop:
%i = phi i64 [ %i.next, %loop ], [ 0, %entry ]
%Ai = getelementptr inbounds double* %A, i64 %i
%Bi = getelementptr inbounds double* %B, i64 %i
%Ci = getelementptr inbounds double* %C, i64 %i
%t1 = load double* %Bi
%t2 = load double* %Ci
%m = fmul double %t1, %t2
store double %m, double* %Ai
%i.next = add nsw i64 %i, 1
%exitcond = icmp eq i64 %i.next, %n
br i1 %exitcond, label %return, label %loop
return:
%q = phi i64 [ 0, %entry ], [ %i.next, %loop ]
ret i64 %q
}
; In this test, the trip count value is used, so full strength reduction
; would not reduce register pressure.
; (though it would reduce register pressure inside the loop...)
; CHECK: count_me_1:
; CHECK: movsd (%rsi,%rax,8), %xmm0
; CHECK: mulsd (%rdx,%rax,8), %xmm0
; CHECK: movsd %xmm0, (%rdi,%rax,8)
; CHECK: incq %rax
; CHECK: cmpq %rax, %rcx
; CHECK: jne
define i64 @count_me_1(double* nocapture %A, double* nocapture %B, double* nocapture %C, i64 %n) nounwind {
entry:
%t0 = icmp sgt i64 %n, 0
br i1 %t0, label %loop, label %return
loop:
%i = phi i64 [ %i.next, %loop ], [ 0, %entry ]
%Ai = getelementptr inbounds double* %A, i64 %i
%Bi = getelementptr inbounds double* %B, i64 %i
%Ci = getelementptr inbounds double* %C, i64 %i
%t1 = load double* %Bi
%t2 = load double* %Ci
%m = fmul double %t1, %t2
store double %m, double* %Ai
%i.next = add nsw i64 %i, 1
%exitcond = icmp eq i64 %i.next, %n
br i1 %exitcond, label %return, label %loop
return:
%q = phi i64 [ 0, %entry ], [ %n, %loop ]
ret i64 %q
}
; Full strength reduction doesn't save any registers here because the
; loop tripcount is a constant.
; CHECK: count_me_2:
; CHECK: movl $10, %eax
; CHECK: align
; CHECK: BB7_1:
; CHECK: movsd -40(%rdi,%rax,8), %xmm0
; CHECK: addsd -40(%rsi,%rax,8), %xmm0
; CHECK: movsd %xmm0, -40(%rdx,%rax,8)
; CHECK: movsd (%rdi,%rax,8), %xmm0
; CHECK: subsd (%rsi,%rax,8), %xmm0
; CHECK: movsd %xmm0, (%rdx,%rax,8)
; CHECK: incq %rax
; CHECK: cmpq $5010, %rax
; CHECK: jne
define void @count_me_2(double* nocapture %A, double* nocapture %B, double* nocapture %C) nounwind {
entry:
br label %loop
loop:
%i = phi i64 [ 0, %entry ], [ %i.next, %loop ]
%i5 = add i64 %i, 5
%Ai = getelementptr double* %A, i64 %i5
%t2 = load double* %Ai
%Bi = getelementptr double* %B, i64 %i5
%t4 = load double* %Bi
%t5 = fadd double %t2, %t4
%Ci = getelementptr double* %C, i64 %i5
store double %t5, double* %Ci
%i10 = add i64 %i, 10
%Ai10 = getelementptr double* %A, i64 %i10
%t9 = load double* %Ai10
%Bi10 = getelementptr double* %B, i64 %i10
%t11 = load double* %Bi10
%t12 = fsub double %t9, %t11
%Ci10 = getelementptr double* %C, i64 %i10
store double %t12, double* %Ci10
%i.next = add i64 %i, 1
%exitcond = icmp eq i64 %i.next, 5000
br i1 %exitcond, label %return, label %loop
return:
ret void
}
; This should be fully strength-reduced to reduce register pressure.
; CHECK: full_me_1:
; CHECK: align
; CHECK: BB8_1:
; CHECK: movsd (%rdi), %xmm0
; CHECK: addsd (%rsi), %xmm0
; CHECK: movsd %xmm0, (%rdx)
; CHECK: movsd 40(%rdi), %xmm0
; CHECK: subsd 40(%rsi), %xmm0
; CHECK: movsd %xmm0, 40(%rdx)
; CHECK: addq $8, %rdi
; CHECK: addq $8, %rsi
; CHECK: addq $8, %rdx
; CHECK: decq %rcx
; CHECK: jne
define void @full_me_1(double* nocapture %A, double* nocapture %B, double* nocapture %C, i64 %n) nounwind {
entry:
br label %loop
loop:
%i = phi i64 [ 0, %entry ], [ %i.next, %loop ]
%i5 = add i64 %i, 5
%Ai = getelementptr double* %A, i64 %i5
%t2 = load double* %Ai
%Bi = getelementptr double* %B, i64 %i5
%t4 = load double* %Bi
%t5 = fadd double %t2, %t4
%Ci = getelementptr double* %C, i64 %i5
store double %t5, double* %Ci
%i10 = add i64 %i, 10
%Ai10 = getelementptr double* %A, i64 %i10
%t9 = load double* %Ai10
%Bi10 = getelementptr double* %B, i64 %i10
%t11 = load double* %Bi10
%t12 = fsub double %t9, %t11
%Ci10 = getelementptr double* %C, i64 %i10
store double %t12, double* %Ci10
%i.next = add i64 %i, 1
%exitcond = icmp eq i64 %i.next, %n
br i1 %exitcond, label %return, label %loop
return:
ret void
}
; This is a variation on full_me_0 in which the 0,+,1 induction variable
; has a non-address use, pinning that value in a register.
; CHECK: count_me_3:
; CHECK: call
; CHECK: movsd (%r15,%r13,8), %xmm0
; CHECK: mulsd (%r14,%r13,8), %xmm0
; CHECK: movsd %xmm0, (%r12,%r13,8)
; CHECK: incq %r13
; CHECK: cmpq %r13, %rbx
; CHECK: jne
declare void @use(i64)
define void @count_me_3(double* nocapture %A, double* nocapture %B, double* nocapture %C, i64 %n) nounwind {
entry:
%t0 = icmp sgt i64 %n, 0
br i1 %t0, label %loop, label %return
loop:
%i = phi i64 [ %i.next, %loop ], [ 0, %entry ]
call void @use(i64 %i)
%Ai = getelementptr inbounds double* %A, i64 %i
%Bi = getelementptr inbounds double* %B, i64 %i
%Ci = getelementptr inbounds double* %C, i64 %i
%t1 = load double* %Bi
%t2 = load double* %Ci
%m = fmul double %t1, %t2
store double %m, double* %Ai
%i.next = add nsw i64 %i, 1
%exitcond = icmp eq i64 %i.next, %n
br i1 %exitcond, label %return, label %loop
return:
ret void
}
; LSR should use only one indvar for the inner loop.
; rdar://7657764
; CHECK: asd:
; CHECK: BB10_5:
; CHECK-NEXT: addl (%r{{[^,]*}},%rdi,4), %e
; CHECK-NEXT: incq %rdi
; CHECK-NEXT: cmpq %rdi, %r{{[^,]*}}
; CHECK-NEXT: jg
%struct.anon = type { i32, [4200 x i32] }
@bars = common global [123123 x %struct.anon] zeroinitializer, align 32 ; <[123123 x %struct.anon]*> [#uses=2]
define i32 @asd(i32 %n) nounwind readonly {
entry:
%0 = icmp sgt i32 %n, 0 ; <i1> [#uses=1]
br i1 %0, label %bb.nph14, label %bb5
bb.nph14: ; preds = %entry
%tmp18 = zext i32 %n to i64 ; <i64> [#uses=1]
br label %bb
bb: ; preds = %bb3, %bb.nph14
%indvar16 = phi i64 [ 0, %bb.nph14 ], [ %indvar.next17, %bb3 ] ; <i64> [#uses=3]
%s.113 = phi i32 [ 0, %bb.nph14 ], [ %s.0.lcssa, %bb3 ] ; <i32> [#uses=2]
%scevgep2526 = getelementptr [123123 x %struct.anon]* @bars, i64 0, i64 %indvar16, i32 0 ; <i32*> [#uses=1]
%1 = load i32* %scevgep2526, align 4 ; <i32> [#uses=2]
%2 = icmp sgt i32 %1, 0 ; <i1> [#uses=1]
br i1 %2, label %bb.nph, label %bb3
bb.nph: ; preds = %bb
%tmp23 = sext i32 %1 to i64 ; <i64> [#uses=1]
br label %bb1
bb1: ; preds = %bb.nph, %bb1
%indvar = phi i64 [ 0, %bb.nph ], [ %tmp19, %bb1 ] ; <i64> [#uses=2]
%s.07 = phi i32 [ %s.113, %bb.nph ], [ %4, %bb1 ] ; <i32> [#uses=1]
%c.08 = getelementptr [123123 x %struct.anon]* @bars, i64 0, i64 %indvar16, i32 1, i64 %indvar ; <i32*> [#uses=1]
%3 = load i32* %c.08, align 4 ; <i32> [#uses=1]
%4 = add nsw i32 %3, %s.07 ; <i32> [#uses=2]
%tmp19 = add i64 %indvar, 1 ; <i64> [#uses=2]
%5 = icmp sgt i64 %tmp23, %tmp19 ; <i1> [#uses=1]
br i1 %5, label %bb1, label %bb3
bb3: ; preds = %bb1, %bb
%s.0.lcssa = phi i32 [ %s.113, %bb ], [ %4, %bb1 ] ; <i32> [#uses=2]
%indvar.next17 = add i64 %indvar16, 1 ; <i64> [#uses=2]
%exitcond = icmp eq i64 %indvar.next17, %tmp18 ; <i1> [#uses=1]
br i1 %exitcond, label %bb5, label %bb
bb5: ; preds = %bb3, %entry
%s.1.lcssa = phi i32 [ 0, %entry ], [ %s.0.lcssa, %bb3 ] ; <i32> [#uses=1]
ret i32 %s.1.lcssa
}