[Hexagon] Generate hardware loop for a vectorized loop

The induction variable in the vectorized loop wasn't
recognized properly, so a hardware loop wasn't generated.

Differential Revision: http://reviews.llvm.org/D9722

llvm-svn: 237388

1 files changed, 93 insertions, 0 deletions

diff --git a/llvm/test/CodeGen/Hexagon/hwloop5.ll b/llvm/test/CodeGen/Hexagon/hwloop5.ll
new file mode 100644
index 00000000000..0886b03cc75
--- /dev/null
+++ b/llvm/test/CodeGen/Hexagon/hwloop5.ll
@@ -0,0 +1,93 @@
+; RUN: llc -O3 -march=hexagon -mcpu=hexagonv5 < %s | FileCheck %s
+;
+; Generate hardware loop when unknown trip count loop is vectorized.
+
+; CHECK: loop0(.LBB{{[0-9]*}}_{{[0-9]*}}, r{{[0-9]+}})
+; CHECK: endloop0
+; CHECK: loop0(.LBB{{[0-9]*}}_{{[0-9]*}}, r{{[0-9]+}})
+; CHECK: endloop0
+
+@A = common global [1000 x i32] zeroinitializer, align 8
+@B = common global [1000 x i32] zeroinitializer, align 8
+
+define i32 @dotprod2(i32 %count) #0 {
+entry.split:
+  %cmp6 = icmp sgt i32 %count, 0
+  br i1 %cmp6, label %polly.cond, label %for.end
+
+for.end.loopexit:
+  br label %for.end
+
+for.end:
+  %sum.0.lcssa.reg2mem.0.load37 = phi i32 [ 0, %entry.split ], [ %p_add34, %polly.loop_if13 ], [ %p_add, %for.end.loopexit ]
+  ret i32 %sum.0.lcssa.reg2mem.0.load37
+
+polly.cond:
+  %0 = icmp sgt i32 %count, 1
+  br i1 %0, label %polly.loop_if, label %polly.loop_if13
+
+polly.loop_exit.loopexit:
+  br label %polly.loop_exit
+
+polly.loop_exit:
+  %1 = phi <2 x i32> [ zeroinitializer, %polly.loop_if ], [ %addp_vec, %polly.loop_exit.loopexit ]
+  %2 = extractelement <2 x i32> %1, i32 0
+  %3 = extractelement <2 x i32> %1, i32 1
+  %add_sum = add i32 %2, %3
+  br label %polly.loop_if13
+
+polly.loop_if:
+  %4 = add i32 %count, -1
+  %leftover_lb = and i32 %4, -2
+  %polly.loop_guard = icmp eq i32 %leftover_lb, 0
+  br i1 %polly.loop_guard, label %polly.loop_exit, label %polly.loop_preheader
+
+polly.stmt.for.body:
+  %addp_vec28 = phi <2 x i32> [ zeroinitializer, %polly.loop_preheader ], [ %addp_vec, %polly.stmt.for.body ]
+  %scevgep.phi = phi i32* [ getelementptr inbounds ([1000 x i32], [1000 x i32]* @A, i32 0, i32 0), %polly.loop_preheader ], [ %scevgep.inc, %polly.stmt.for.body ]
+  %scevgep9.phi = phi i32* [ getelementptr inbounds ([1000 x i32], [1000 x i32]* @B, i32 0, i32 0), %polly.loop_preheader ], [ %scevgep9.inc, %polly.stmt.for.body ]
+  %polly.indvar = phi i32 [ 0, %polly.loop_preheader ], [ %polly.indvar_next, %polly.stmt.for.body ]
+  %vector_ptr = bitcast i32* %scevgep.phi to <2 x i32>*
+  %_p_vec_full = load <2 x i32>, <2 x i32>* %vector_ptr, align 8
+  %vector_ptr10 = bitcast i32* %scevgep9.phi to <2 x i32>*
+  %_p_vec_full11 = load <2 x i32>, <2 x i32>* %vector_ptr10, align 8
+  %mulp_vec = mul <2 x i32> %_p_vec_full11, %_p_vec_full
+  %addp_vec = add <2 x i32> %mulp_vec, %addp_vec28
+  %polly.indvar_next = add nsw i32 %polly.indvar, 2
+  %polly.loop_cond = icmp eq i32 %polly.indvar, %polly.adjust_ub
+  %scevgep.inc = getelementptr i32, i32* %scevgep.phi, i32 2
+  %scevgep9.inc = getelementptr i32, i32* %scevgep9.phi, i32 2
+  br i1 %polly.loop_cond, label %polly.loop_exit.loopexit, label %polly.stmt.for.body
+
+polly.loop_preheader:
+  %polly.adjust_ub = add i32 %leftover_lb, -2
+  br label %polly.stmt.for.body
+
+polly.loop_if13:
+  %p_add34 = phi i32 [ 0, %polly.cond ], [ %add_sum, %polly.loop_exit ]
+  %merge.lb = phi i32 [ 0, %polly.cond ], [ %leftover_lb, %polly.loop_exit ]
+  %polly.loop_guard17 = icmp slt i32 %merge.lb, %count
+  br i1 %polly.loop_guard17, label %polly.loop_preheader15, label %for.end
+
+polly.stmt.for.body22:
+  %p_add30 = phi i32 [ %p_add34, %polly.loop_preheader15 ], [ %p_add, %polly.stmt.for.body22 ]
+  %polly.indvar18 = phi i32 [ %merge.lb, %polly.loop_preheader15 ], [ %polly.indvar_next19, %polly.stmt.for.body22 ]
+  %5 = tail call i32 @llvm.annotation.i32(i32 %polly.indvar18, i8* null, i8* null, i32 0), !polly.loop.smallTripCount !0
+  %scevgep23 = getelementptr [1000 x i32], [1000 x i32]* @A, i32 0, i32 %polly.indvar18
+  %_p_scalar_ = load i32, i32* %scevgep23, align 4
+  %scevgep24 = getelementptr [1000 x i32], [1000 x i32]* @B, i32 0, i32 %polly.indvar18
+  %_p_scalar_25 = load i32, i32* %scevgep24, align 4
+  %p_mul = mul nsw i32 %_p_scalar_25, %_p_scalar_
+  %p_add = add nsw i32 %p_mul, %p_add30
+  %polly.indvar_next19 = add nsw i32 %polly.indvar18, 1
+  %polly.loop_cond21 = icmp slt i32 %polly.indvar18, %polly.adjust_ub20
+  br i1 %polly.loop_cond21, label %polly.stmt.for.body22, label %for.end.loopexit
+
+polly.loop_preheader15:
+  %polly.adjust_ub20 = add i32 %count, -1
+  br label %polly.stmt.for.body22
+}
+
+declare i32 @llvm.annotation.i32(i32, i8*, i8*, i32) #1
+
+!0 = !{}