[llvm] d927984 - [AArch64][GlobalISel] Widen G_PHI before clamping it during legalization
Jessica Paquette via llvm-commits
llvm-commits at lists.llvm.org
Wed Aug 4 10:26:09 PDT 2021
Author: Jessica Paquette
Date: 2021-08-04T10:25:14-07:00
New Revision: d9279843b1bafcfb1f540d3093b86023025b6717
URL: https://github.com/llvm/llvm-project/commit/d9279843b1bafcfb1f540d3093b86023025b6717
DIFF: https://github.com/llvm/llvm-project/commit/d9279843b1bafcfb1f540d3093b86023025b6717.diff
LOG: [AArch64][GlobalISel] Widen G_PHI before clamping it during legalization
This allows us to handle weird types like s88; we first widen to s128, then
clamp back down to s64.
https://godbolt.org/z/9xqbP46Mz
Also this makes it possible for GISel to legalize the case in pr48188.ll. It
now does the same thing as SDAG, although regalloc chooses different registers.
Differential Revision: https://reviews.llvm.org/D107417
Added:
Modified:
llvm/lib/Target/AArch64/GISel/AArch64LegalizerInfo.cpp
llvm/test/CodeGen/AArch64/GlobalISel/legalize-phi.mir
llvm/test/CodeGen/AArch64/pr48188.ll
Removed:
################################################################################
diff --git a/llvm/lib/Target/AArch64/GISel/AArch64LegalizerInfo.cpp b/llvm/lib/Target/AArch64/GISel/AArch64LegalizerInfo.cpp
index 279fdcf210be..7849bb2d8859 100644
--- a/llvm/lib/Target/AArch64/GISel/AArch64LegalizerInfo.cpp
+++ b/llvm/lib/Target/AArch64/GISel/AArch64LegalizerInfo.cpp
@@ -97,8 +97,8 @@ AArch64LegalizerInfo::AArch64LegalizerInfo(const AArch64Subtarget &ST)
getActionDefinitionsBuilder(G_PHI).legalFor({p0, s16, s32, s64})
.legalFor(PackedVectorAllTypeList)
- .clampScalar(0, s16, s64)
- .widenScalarToNextPow2(0);
+ .widenScalarToNextPow2(0)
+ .clampScalar(0, s16, s64);
getActionDefinitionsBuilder(G_BSWAP)
.legalFor({s32, s64, v4s32, v2s32, v2s64})
diff --git a/llvm/test/CodeGen/AArch64/GlobalISel/legalize-phi.mir b/llvm/test/CodeGen/AArch64/GlobalISel/legalize-phi.mir
index 78b1be919024..d1dd27f4b462 100644
--- a/llvm/test/CodeGen/AArch64/GlobalISel/legalize-phi.mir
+++ b/llvm/test/CodeGen/AArch64/GlobalISel/legalize-phi.mir
@@ -624,3 +624,44 @@ body: |
$q0 = COPY %3(<16 x s8>)
RET_ReallyLR
...
+---
+name: s88
+tracksRegLiveness: true
+liveins:
+body: |
+ ; CHECK-LABEL: name: s88
+ ; CHECK: bb.0:
+ ; CHECK: successors: %bb.1(0x40000000), %bb.2(0x40000000)
+ ; CHECK: liveins: $x0
+ ; CHECK: %cond:_(s1) = G_IMPLICIT_DEF
+ ; CHECK: G_BRCOND %cond(s1), %bb.1
+ ; CHECK: G_BR %bb.2
+ ; CHECK: bb.1:
+ ; CHECK: successors: %bb.3(0x80000000)
+ ; CHECK: [[DEF:%[0-9]+]]:_(s64) = G_IMPLICIT_DEF
+ ; CHECK: G_BR %bb.3
+ ; CHECK: bb.2:
+ ; CHECK: successors: %bb.3(0x80000000)
+ ; CHECK: [[DEF1:%[0-9]+]]:_(s64) = G_IMPLICIT_DEF
+ ; CHECK: bb.3:
+ ; CHECK: [[PHI:%[0-9]+]]:_(s64) = G_PHI [[DEF]](s64), %bb.1, [[DEF1]](s64), %bb.2
+ ; CHECK: $x0 = COPY [[PHI]](s64)
+ ; CHECK: RET_ReallyLR implicit $x0
+ bb.0:
+ successors: %bb.1(0x40000000), %bb.2(0x40000000)
+ liveins: $x0
+ %cond:_(s1) = G_IMPLICIT_DEF
+ G_BRCOND %cond(s1), %bb.1
+ G_BR %bb.2
+ bb.1:
+ successors: %bb.3(0x80000000)
+ %imp_1:_(s88) = G_IMPLICIT_DEF
+ G_BR %bb.3
+ bb.2:
+ successors: %bb.3(0x80000000)
+ %imp_2:_(s88) = G_IMPLICIT_DEF
+ bb.3:
+ %phi:_(s88) = G_PHI %imp_1:_(s88), %bb.1, %imp_2:_(s88), %bb.2
+ %trunc:_(s64) = G_TRUNC %phi
+ $x0 = COPY %trunc
+ RET_ReallyLR implicit $x0
diff --git a/llvm/test/CodeGen/AArch64/pr48188.ll b/llvm/test/CodeGen/AArch64/pr48188.ll
index 599021674e85..d01069696572 100644
--- a/llvm/test/CodeGen/AArch64/pr48188.ll
+++ b/llvm/test/CodeGen/AArch64/pr48188.ll
@@ -1,23 +1,40 @@
; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
-; RUN: llc -O0 -mtriple=aarch64-unknown-linux-gnu < %s | FileCheck %s
+; RUN: llc -O0 -mtriple=aarch64-unknown-linux-gnu < %s | FileCheck %s --check-prefix=GISEL
+; RUN: llc -O0 -global-isel=0 -mtriple=aarch64-unknown-linux-gnu < %s | FileCheck %s --check-prefix=SDAG
-; GlobalISel cannot legalize this phi, so we fall back to SDAG.
+; Verify that GISel and SDAG do the same thing for this phi (modulo regalloc)
define void @test() nounwind {
-; CHECK-LABEL: test:
-; CHECK: // %bb.0: // %entry
-; CHECK-NEXT: sub sp, sp, #16
-; CHECK-NEXT: mov x1, xzr
-; CHECK-NEXT: mov x0, x1
-; CHECK-NEXT: str x1, [sp] // 8-byte Folded Spill
-; CHECK-NEXT: str x0, [sp, #8] // 8-byte Folded Spill
-; CHECK-NEXT: b .LBB0_1
-; CHECK-NEXT: .LBB0_1: // %loop
-; CHECK-NEXT: // =>This Inner Loop Header: Depth=1
-; CHECK-NEXT: ldr x0, [sp, #8] // 8-byte Folded Reload
-; CHECK-NEXT: ldr x1, [sp] // 8-byte Folded Reload
-; CHECK-NEXT: str x1, [sp] // 8-byte Folded Spill
-; CHECK-NEXT: str x0, [sp, #8] // 8-byte Folded Spill
-; CHECK-NEXT: b .LBB0_1
+; GISEL-LABEL: test:
+; GISEL: // %bb.0: // %entry
+; GISEL-NEXT: sub sp, sp, #16
+; GISEL-NEXT: mov x8, xzr
+; GISEL-NEXT: mov x9, x8
+; GISEL-NEXT: str x9, [sp] // 8-byte Folded Spill
+; GISEL-NEXT: str x8, [sp, #8] // 8-byte Folded Spill
+; GISEL-NEXT: b .LBB0_1
+; GISEL-NEXT: .LBB0_1: // %loop
+; GISEL-NEXT: // =>This Inner Loop Header: Depth=1
+; GISEL-NEXT: ldr x8, [sp, #8] // 8-byte Folded Reload
+; GISEL-NEXT: ldr x9, [sp] // 8-byte Folded Reload
+; GISEL-NEXT: str x9, [sp] // 8-byte Folded Spill
+; GISEL-NEXT: str x8, [sp, #8] // 8-byte Folded Spill
+; GISEL-NEXT: b .LBB0_1
+;
+; SDAG-LABEL: test:
+; SDAG: // %bb.0: // %entry
+; SDAG-NEXT: sub sp, sp, #16
+; SDAG-NEXT: mov x1, xzr
+; SDAG-NEXT: mov x0, x1
+; SDAG-NEXT: str x1, [sp] // 8-byte Folded Spill
+; SDAG-NEXT: str x0, [sp, #8] // 8-byte Folded Spill
+; SDAG-NEXT: b .LBB0_1
+; SDAG-NEXT: .LBB0_1: // %loop
+; SDAG-NEXT: // =>This Inner Loop Header: Depth=1
+; SDAG-NEXT: ldr x0, [sp, #8] // 8-byte Folded Reload
+; SDAG-NEXT: ldr x1, [sp] // 8-byte Folded Reload
+; SDAG-NEXT: str x1, [sp] // 8-byte Folded Spill
+; SDAG-NEXT: str x0, [sp, #8] // 8-byte Folded Spill
+; SDAG-NEXT: b .LBB0_1
entry:
br label %loop
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