-; RUN: llc -mtriple=i686-linux -enable-block-placement < %s | FileCheck %s
+; RUN: llc -mtriple=i686-linux < %s | FileCheck %s
declare void @error(i32 %i, i32 %a, i32 %b)
; Check that we sink cold loop blocks after the hot loop body.
; CHECK: test_loop_cold_blocks:
; CHECK: %entry
+; CHECK: %unlikely1
+; CHECK: %unlikely2
; CHECK: %body1
; CHECK: %body2
; CHECK: %body3
-; CHECK: %unlikely1
-; CHECK: %unlikely2
; CHECK: %exit
entry:
ret i32 %base
}
+define i32 @test_no_loop_rotate(i32 %i, i32* %a) {
+; Check that we don't try to rotate a loop which is already laid out with
+; fallthrough opportunities into the top and out of the bottom.
+; CHECK: test_no_loop_rotate:
+; CHECK: %entry
+; CHECK: %body0
+; CHECK: %body1
+; CHECK: %exit
+
+entry:
+ br label %body0
+
+body0:
+ %iv = phi i32 [ 0, %entry ], [ %next, %body1 ]
+ %base = phi i32 [ 0, %entry ], [ %sum, %body1 ]
+ %arrayidx = getelementptr inbounds i32* %a, i32 %iv
+ %0 = load i32* %arrayidx
+ %sum = add nsw i32 %0, %base
+ %bailcond1 = icmp eq i32 %sum, 42
+ br i1 %bailcond1, label %exit, label %body1
+
+body1:
+ %next = add i32 %iv, 1
+ %exitcond = icmp eq i32 %next, %i
+ br i1 %exitcond, label %exit, label %body0
+
+exit:
+ ret i32 %base
+}
+
+define void @test_loop_rotate_reversed_blocks() {
+; This test case (greatly reduced from an Olden bencmark) ensures that the loop
+; rotate implementation doesn't assume that loops are laid out in a particular
+; order. The first loop will get split into two basic blocks, with the loop
+; header coming after the loop latch.
+;
+; CHECK: test_loop_rotate_reversed_blocks
+; CHECK: %entry
+; Look for a jump into the middle of the loop, and no branches mid-way.
+; CHECK: jmp
+; CHECK: %loop1
+; CHECK-NOT: j{{\w*}} .LBB{{.*}}
+; CHECK: %loop1
+; CHECK: je
+
+entry:
+ %cond1 = load volatile i1* undef
+ br i1 %cond1, label %loop2.preheader, label %loop1
+
+loop1:
+ call i32 @f()
+ %cond2 = load volatile i1* undef
+ br i1 %cond2, label %loop2.preheader, label %loop1
+
+loop2.preheader:
+ call i32 @f()
+ %cond3 = load volatile i1* undef
+ br i1 %cond3, label %exit, label %loop2
+
+loop2:
+ call i32 @f()
+ %cond4 = load volatile i1* undef
+ br i1 %cond4, label %exit, label %loop2
+
+exit:
+ ret void
+}
+
define i32 @test_loop_align(i32 %i, i32* %a) {
; Check that we provide basic loop body alignment with the block placement
; pass.
; single-source GCC.
; CHECK: unnatural_cfg2
; CHECK: %entry
-; CHECK: %loop.header
; CHECK: %loop.body1
; CHECK: %loop.body2
; CHECK: %loop.body3
; CHECK: %loop.body4
; CHECK: %loop.inner2.begin
; The loop.inner2.end block is folded
+; CHECK: %loop.header
; CHECK: %bail
entry:
; CHECK: test_unnatural_cfg_backwards_inner_loop
; CHECK: %entry
; CHECK: %body
-; CHECK: %loop1
; CHECK: %loop2b
+; CHECK: %loop1
; CHECK: %loop2a
entry:
exit:
ret void
}
+
+define void @benchmark_heapsort(i32 %n, double* nocapture %ra) {
+; This test case comes from the heapsort benchmark, and exemplifies several
+; important aspects to block placement in the presence of loops:
+; 1) Loop rotation needs to *ensure* that the desired exiting edge can be
+; a fallthrough.
+; 2) The exiting edge from the loop which is rotated to be laid out at the
+; bottom of the loop needs to be exiting into the nearest enclosing loop (to
+; which there is an exit). Otherwise, we force that enclosing loop into
+; strange layouts that are siginificantly less efficient, often times maing
+; it discontiguous.
+;
+; CHECK: @benchmark_heapsort
+; CHECK: %entry
+; First rotated loop top.
+; CHECK: .align
+; CHECK: %while.end
+; CHECK: %for.cond
+; CHECK: %if.then
+; CHECK: %if.else
+; CHECK: %if.end10
+; Second rotated loop top
+; CHECK: .align
+; CHECK: %if.then24
+; CHECK: %while.cond.outer
+; Third rotated loop top
+; CHECK: .align
+; CHECK: %while.cond
+; CHECK: %while.body
+; CHECK: %land.lhs.true
+; CHECK: %if.then19
+; CHECK: %if.then19
+; CHECK: %if.then8
+; CHECK: ret
+
+entry:
+ %shr = ashr i32 %n, 1
+ %add = add nsw i32 %shr, 1
+ %arrayidx3 = getelementptr inbounds double* %ra, i64 1
+ br label %for.cond
+
+for.cond:
+ %ir.0 = phi i32 [ %n, %entry ], [ %ir.1, %while.end ]
+ %l.0 = phi i32 [ %add, %entry ], [ %l.1, %while.end ]
+ %cmp = icmp sgt i32 %l.0, 1
+ br i1 %cmp, label %if.then, label %if.else
+
+if.then:
+ %dec = add nsw i32 %l.0, -1
+ %idxprom = sext i32 %dec to i64
+ %arrayidx = getelementptr inbounds double* %ra, i64 %idxprom
+ %0 = load double* %arrayidx, align 8
+ br label %if.end10
+
+if.else:
+ %idxprom1 = sext i32 %ir.0 to i64
+ %arrayidx2 = getelementptr inbounds double* %ra, i64 %idxprom1
+ %1 = load double* %arrayidx2, align 8
+ %2 = load double* %arrayidx3, align 8
+ store double %2, double* %arrayidx2, align 8
+ %dec6 = add nsw i32 %ir.0, -1
+ %cmp7 = icmp eq i32 %dec6, 1
+ br i1 %cmp7, label %if.then8, label %if.end10
+
+if.then8:
+ store double %1, double* %arrayidx3, align 8
+ ret void
+
+if.end10:
+ %ir.1 = phi i32 [ %ir.0, %if.then ], [ %dec6, %if.else ]
+ %l.1 = phi i32 [ %dec, %if.then ], [ %l.0, %if.else ]
+ %rra.0 = phi double [ %0, %if.then ], [ %1, %if.else ]
+ %add31 = add nsw i32 %ir.1, 1
+ br label %while.cond.outer
+
+while.cond.outer:
+ %j.0.ph.in = phi i32 [ %l.1, %if.end10 ], [ %j.1, %if.then24 ]
+ %j.0.ph = shl i32 %j.0.ph.in, 1
+ br label %while.cond
+
+while.cond:
+ %j.0 = phi i32 [ %add31, %if.end20 ], [ %j.0.ph, %while.cond.outer ]
+ %cmp11 = icmp sgt i32 %j.0, %ir.1
+ br i1 %cmp11, label %while.end, label %while.body
+
+while.body:
+ %cmp12 = icmp slt i32 %j.0, %ir.1
+ br i1 %cmp12, label %land.lhs.true, label %if.end20
+
+land.lhs.true:
+ %idxprom13 = sext i32 %j.0 to i64
+ %arrayidx14 = getelementptr inbounds double* %ra, i64 %idxprom13
+ %3 = load double* %arrayidx14, align 8
+ %add15 = add nsw i32 %j.0, 1
+ %idxprom16 = sext i32 %add15 to i64
+ %arrayidx17 = getelementptr inbounds double* %ra, i64 %idxprom16
+ %4 = load double* %arrayidx17, align 8
+ %cmp18 = fcmp olt double %3, %4
+ br i1 %cmp18, label %if.then19, label %if.end20
+
+if.then19:
+ br label %if.end20
+
+if.end20:
+ %j.1 = phi i32 [ %add15, %if.then19 ], [ %j.0, %land.lhs.true ], [ %j.0, %while.body ]
+ %idxprom21 = sext i32 %j.1 to i64
+ %arrayidx22 = getelementptr inbounds double* %ra, i64 %idxprom21
+ %5 = load double* %arrayidx22, align 8
+ %cmp23 = fcmp olt double %rra.0, %5
+ br i1 %cmp23, label %if.then24, label %while.cond
+
+if.then24:
+ %idxprom27 = sext i32 %j.0.ph.in to i64
+ %arrayidx28 = getelementptr inbounds double* %ra, i64 %idxprom27
+ store double %5, double* %arrayidx28, align 8
+ br label %while.cond.outer
+
+while.end:
+ %idxprom33 = sext i32 %j.0.ph.in to i64
+ %arrayidx34 = getelementptr inbounds double* %ra, i64 %idxprom33
+ store double %rra.0, double* %arrayidx34, align 8
+ br label %for.cond
+}
projects / oota-llvm.git / blobdiff