From 7f3d02471d04bef0062790c0b79151a9a6fe8266 Mon Sep 17 00:00:00 2001 From: Evan Cheng Date: Fri, 26 Oct 2007 01:56:11 +0000 Subject: Loosen up iv reuse to allow reuse of the same stride but a larger type when truncating from the larger type to smaller type is free. e.g. Turns this loop: LBB1_1: # entry.bb_crit_edge xorl %ecx, %ecx xorw %dx, %dx movw %dx, %si LBB1_2: # bb movl L_X$non_lazy_ptr, %edi movw %si, (%edi) movl L_Y$non_lazy_ptr, %edi movw %dx, (%edi) addw $4, %dx incw %si incl %ecx cmpl %eax, %ecx jne LBB1_2 # bb into LBB1_1: # entry.bb_crit_edge xorl %ecx, %ecx xorw %dx, %dx LBB1_2: # bb movl L_X$non_lazy_ptr, %esi movw %cx, (%esi) movl L_Y$non_lazy_ptr, %esi movw %dx, (%esi) addw $4, %dx incl %ecx cmpl %eax, %ecx jne LBB1_2 # bb llvm-svn: 43375 --- llvm/test/CodeGen/X86/loop-strength-reduce5.ll | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) create mode 100644 llvm/test/CodeGen/X86/loop-strength-reduce5.ll (limited to 'llvm/test/CodeGen/X86/loop-strength-reduce5.ll') diff --git a/llvm/test/CodeGen/X86/loop-strength-reduce5.ll b/llvm/test/CodeGen/X86/loop-strength-reduce5.ll new file mode 100644 index 00000000000..6e037e2aca3 --- /dev/null +++ b/llvm/test/CodeGen/X86/loop-strength-reduce5.ll @@ -0,0 +1,23 @@ +; RUN: llvm-as < %s | llc -march=x86 | grep inc | count 1 + +@X = weak global i16 0 ; [#uses=1] +@Y = weak global i16 0 ; [#uses=1] + +define void @foo(i32 %N) { +entry: + %tmp1019 = icmp sgt i32 %N, 0 ; [#uses=1] + br i1 %tmp1019, label %bb, label %return + +bb: ; preds = %bb, %entry + %i.014.0 = phi i32 [ 0, %entry ], [ %indvar.next, %bb ] ; [#uses=2] + %tmp1 = trunc i32 %i.014.0 to i16 ; [#uses=2] + volatile store i16 %tmp1, i16* @X, align 2 + %tmp34 = shl i16 %tmp1, 2 ; [#uses=1] + volatile store i16 %tmp34, i16* @Y, align 2 + %indvar.next = add i32 %i.014.0, 1 ; [#uses=2] + %exitcond = icmp eq i32 %indvar.next, %N ; [#uses=1] + br i1 %exitcond, label %return, label %bb + +return: ; preds = %bb, %entry + ret void +} -- cgit v1.2.3