| Age | Commit message (Collapse) | Author | |
|---|---|---|---|
| 2013-04-25 | ARM cost model: Integer div and rem is lowered to a function call | Arnold Schwaighofer | |
| Reflect this in the cost model. I observed this in MiBench/consumer-lame. radar://13354716 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180576 91177308-0d34-0410-b5e6-96231b3b80d8 | |||
| 2013-04-21 | Legalize vector truncates by parts rather than just splitting. | Jim Grosbach | |
| Rather than just splitting the input type and hoping for the best, apply a bit more cleverness. Just splitting the types until the source is legal often leads to an illegal result time, which is then widened and a scalarization step is introduced which leads to truly horrible code generation. With the loop vectorizer, these sorts of operations are much more common, and so it's worth extra effort to do them well. Add a legalization hook for the operands of a TRUNCATE node, which will be encountered after the result type has been legalized, but if the operand type is still illegal. If simple splitting of both types ends up with the result type of each half still being legal, just do that (v16i16 -> v16i8 on ARM, for example). If, however, that would result in an illegal result type (v8i32 -> v8i8 on ARM, for example), we can get more clever with power-two vectors. Specifically, split the input type, but also widen the result element size, then concatenate the halves and truncate again. For example on ARM, To perform a "%res = v8i8 trunc v8i32 %in" we transform to: %inlo = v4i32 extract_subvector %in, 0 %inhi = v4i32 extract_subvector %in, 4 %lo16 = v4i16 trunc v4i32 %inlo %hi16 = v4i16 trunc v4i32 %inhi %in16 = v8i16 concat_vectors v4i16 %lo16, v4i16 %hi16 %res = v8i8 trunc v8i16 %in16 This allows instruction selection to generate three VMOVN instructions instead of a sequences of moves, stores and loads. Update the ARMTargetTransformInfo to take this improved legalization into account. Consider the simplified IR: define <16 x i8> @test1(<16 x i32>* %ap) { %a = load <16 x i32>* %ap %tmp = trunc <16 x i32> %a to <16 x i8> ret <16 x i8> %tmp } define <8 x i8> @test2(<8 x i32>* %ap) { %a = load <8 x i32>* %ap %tmp = trunc <8 x i32> %a to <8 x i8> ret <8 x i8> %tmp } Previously, we would generate the truly hideous: .syntax unified .section __TEXT,__text,regular,pure_instructions .globl _test1 .align 2 _test1: @ @test1 @ BB#0: push {r7} mov r7, sp sub sp, sp, #20 bic sp, sp, #7 add r1, r0, #48 add r2, r0, #32 vld1.64 {d24, d25}, [r0:128] vld1.64 {d16, d17}, [r1:128] vld1.64 {d18, d19}, [r2:128] add r1, r0, #16 vmovn.i32 d22, q8 vld1.64 {d16, d17}, [r1:128] vmovn.i32 d20, q9 vmovn.i32 d18, q12 vmov.u16 r0, d22[3] strb r0, [sp, #15] vmov.u16 r0, d22[2] strb r0, [sp, #14] vmov.u16 r0, d22[1] strb r0, [sp, #13] vmov.u16 r0, d22[0] vmovn.i32 d16, q8 strb r0, [sp, #12] vmov.u16 r0, d20[3] strb r0, [sp, #11] vmov.u16 r0, d20[2] strb r0, [sp, #10] vmov.u16 r0, d20[1] strb r0, [sp, #9] vmov.u16 r0, d20[0] strb r0, [sp, #8] vmov.u16 r0, d18[3] strb r0, [sp, #3] vmov.u16 r0, d18[2] strb r0, [sp, #2] vmov.u16 r0, d18[1] strb r0, [sp, #1] vmov.u16 r0, d18[0] strb r0, [sp] vmov.u16 r0, d16[3] strb r0, [sp, #7] vmov.u16 r0, d16[2] strb r0, [sp, #6] vmov.u16 r0, d16[1] strb r0, [sp, #5] vmov.u16 r0, d16[0] strb r0, [sp, #4] vldmia sp, {d16, d17} vmov r0, r1, d16 vmov r2, r3, d17 mov sp, r7 pop {r7} bx lr .globl _test2 .align 2 _test2: @ @test2 @ BB#0: push {r7} mov r7, sp sub sp, sp, #12 bic sp, sp, #7 vld1.64 {d16, d17}, [r0:128] add r0, r0, #16 vld1.64 {d20, d21}, [r0:128] vmovn.i32 d18, q8 vmov.u16 r0, d18[3] vmovn.i32 d16, q10 strb r0, [sp, #3] vmov.u16 r0, d18[2] strb r0, [sp, #2] vmov.u16 r0, d18[1] strb r0, [sp, #1] vmov.u16 r0, d18[0] strb r0, [sp] vmov.u16 r0, d16[3] strb r0, [sp, #7] vmov.u16 r0, d16[2] strb r0, [sp, #6] vmov.u16 r0, d16[1] strb r0, [sp, #5] vmov.u16 r0, d16[0] strb r0, [sp, #4] ldm sp, {r0, r1} mov sp, r7 pop {r7} bx lr Now, however, we generate the much more straightforward: .syntax unified .section __TEXT,__text,regular,pure_instructions .globl _test1 .align 2 _test1: @ @test1 @ BB#0: add r1, r0, #48 add r2, r0, #32 vld1.64 {d20, d21}, [r0:128] vld1.64 {d16, d17}, [r1:128] add r1, r0, #16 vld1.64 {d18, d19}, [r2:128] vld1.64 {d22, d23}, [r1:128] vmovn.i32 d17, q8 vmovn.i32 d16, q9 vmovn.i32 d18, q10 vmovn.i32 d19, q11 vmovn.i16 d17, q8 vmovn.i16 d16, q9 vmov r0, r1, d16 vmov r2, r3, d17 bx lr .globl _test2 .align 2 _test2: @ @test2 @ BB#0: vld1.64 {d16, d17}, [r0:128] add r0, r0, #16 vld1.64 {d18, d19}, [r0:128] vmovn.i32 d16, q8 vmovn.i32 d17, q9 vmovn.i16 d16, q8 vmov r0, r1, d16 bx lr git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179989 91177308-0d34-0410-b5e6-96231b3b80d8 | |||
| 2013-03-19 | Improve long vector sext/zext lowering on ARM | Renato Golin | |
| The ARM backend currently has poor codegen for long sext/zext operations, such as v8i8 -> v8i32. This patch addresses this by performing a custom expansion in ARMISelLowering. It also adds/changes the cost of such lowering in ARMTTI. This partially addresses PR14867. Patch by Pete Couperus git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177380 91177308-0d34-0410-b5e6-96231b3b80d8 | |||
| 2013-03-18 | ARM cost model: Make some vector integer to float casts cheaper | Arnold Schwaighofer | |
| The default logic marks them as too expensive. For example, before this patch we estimated: cost of 16 for instruction: %r = uitofp <4 x i16> %v0 to <4 x float> While this translates to: vmovl.u16 q8, d16 vcvt.f32.u32 q8, q8 All other costs are left to the values assigned by the fallback logic. Theses costs are mostly reasonable in the sense that they get progressively more expensive as the instruction sequences emitted get longer. radar://13445992 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177334 91177308-0d34-0410-b5e6-96231b3b80d8 | |||
| 2013-03-18 | ARM cost model: Correct cost for some cheap float to integer conversions | Arnold Schwaighofer | |
| Fix cost of some "cheap" cast instructions. Before this patch we used to estimate for example: cost of 16 for instruction: %r = fptoui <4 x float> %v0 to <4 x i16> While we would emit: vcvt.s32.f32 q8, q8 vmovn.i32 d16, q8 vuzp.8 d16, d17 All other costs are left to the values assigned by the fallback logic. Theses costs are mostly reasonable in the sense that they get progressively more expensive as the instruction sequences emitted get longer. radar://13434072 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177333 91177308-0d34-0410-b5e6-96231b3b80d8 | |||
| 2013-03-15 | ARM cost model: Fix costs for some vector selects | Arnold Schwaighofer | |
| I was too pessimistic in r177105. Vector selects that fit into a legal register type lower just fine. I was mislead by the code fragment that I was using. The stores/loads that I saw in those cases came from lowering the conditional off an address. Changing the code fragment to: %T0_3 = type <8 x i18> %T1_3 = type <8 x i1> define void @func_blend3(%T0_3* %loadaddr, %T0_3* %loadaddr2, %T1_3* %blend, %T0_3* %storeaddr) { %v0 = load %T0_3* %loadaddr %v1 = load %T0_3* %loadaddr2 ==> FROM: ;%c = load %T1_3* %blend ==> TO: %c = icmp slt %T0_3 %v0, %v1 ==> USE: %r = select %T1_3 %c, %T0_3 %v0, %T0_3 %v1 store %T0_3 %r, %T0_3* %storeaddr ret void } revealed this mistake. radar://13403975 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177170 91177308-0d34-0410-b5e6-96231b3b80d8 | |||
| 2013-03-15 | ARM cost model: Fix cost of fptrunc and fpext instructions | Arnold Schwaighofer | |
| A vector fptrunc and fpext simply gets split into scalar instructions. radar://13192358 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177159 91177308-0d34-0410-b5e6-96231b3b80d8 | |||
| 2013-03-14 | ARM cost model: Increase cost of some vector selects we do terrible on | Arnold Schwaighofer | |
| By terrible I mean we store/load from the stack. This matters on PAQp8 in _Z5trainPsS_ii (which is inlined into Mixer::update) where we decide to vectorize a loop with a VF of 8 resulting in a 25% degradation on a cortex-a8. LV: Found an estimated cost of 2 for VF 8 For instruction: icmp slt i32 LV: Found an estimated cost of 2 for VF 8 For instruction: select i1, i32, i32 The bug that tracks the CodeGen part is PR14868. radar://13403975 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177105 91177308-0d34-0410-b5e6-96231b3b80d8 | |||
| 2013-03-12 | ARM cost model: Increase the cost for vector casts that use the stack | Arnold Schwaighofer | |
| Increase the cost of v8/v16-i8 to v8/v16-i32 casts and truncates as the backend currently lowers those using stack accesses. This was responsible for a significant degradation on MultiSource/Benchmarks/Trimaran/enc-pc1/enc-pc1 where we vectorize one loop to a vector factor of 16. After this patch we select a vector factor of 4 which will generate reasonable code. unsigned char cle[32]; void test(short c) { unsigned short compte; for (compte = 0; compte <= 31; compte++) { cle[compte] = cle[compte] ^ c; } } radar://13220512 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176898 91177308-0d34-0410-b5e6-96231b3b80d8 | |||
| 2013-02-12 | ARM cost model: Add vector reverse shuffle costs | Arnold Schwaighofer | |
| A reverse shuffle is lowered to a vrev and possibly a vext instruction (quad word). radar://13171406 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174933 91177308-0d34-0410-b5e6-96231b3b80d8 | |||
| 2013-02-08 | ARM cost model: Address computation in vector mem ops not free | Arnold Schwaighofer | |
| Adds a function to target transform info to query for the cost of address computation. The cost model analysis pass now also queries this interface. The code in LoopVectorize adds the cost of address computation as part of the memory instruction cost calculation. Only there, we know whether the instruction will be scalarized or not. Increase the penality for inserting in to D registers on swift. This becomes necessary because we now always assume that address computation has a cost and three is a closer value to the architecture. radar://13097204 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174713 91177308-0d34-0410-b5e6-96231b3b80d8 | |||
| 2013-02-07 | ARM cost model: Add costs for vector selects | Arnold Schwaighofer | |
| Vector selects are cheap on NEON. They get lowered to a vbsl instruction. radar://13158753 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174631 91177308-0d34-0410-b5e6-96231b3b80d8 | |||
| 2013-02-05 | ARM cost model: Cost for scalar integer casts and floating point conversions | Arnold Schwaighofer | |
| Also adds some costs for vector integer float conversions. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174371 91177308-0d34-0410-b5e6-96231b3b80d8 | |||
| 2013-02-04 | ARM cost model: Penalize insertelement into D subregisters | Arnold Schwaighofer | |
| Swift has a renaming dependency if we load into D subregisters. We don't have a way of distinguishing between insertelement operations of values from loads and other values. Therefore, we are pessimistic for now (The performance problem showed up in example 14 of gcc-loops). radar://13096933 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174300 91177308-0d34-0410-b5e6-96231b3b80d8 | |||
