Reapply "RegAlloc: Fix verifier error after failed allocation (#119690)" #128400
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This was referenced Feb 23, 2025
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@llvm/pr-subscribers-backend-x86 @llvm/pr-subscribers-backend-amdgpu Author: Matt Arsenault (arsenm) ChangesReapply "RegAlloc: Fix verifier error after failed allocation (#119690)" This reverts commit 0c50054. Reapply with more fixes to avoid expensive_checks failures. Make sure to Move physreg handling. Not sure if necessary Remove intervals from regunits. Not sure if necessary Full diff: https://github.com/llvm/llvm-project/pull/128400.diff 10 Files Affected:
diff --git a/llvm/lib/CodeGen/RegAllocBase.cpp b/llvm/lib/CodeGen/RegAllocBase.cpp
index 50addcbcca065..d66d396a15018 100644
--- a/llvm/lib/CodeGen/RegAllocBase.cpp
+++ b/llvm/lib/CodeGen/RegAllocBase.cpp
@@ -65,6 +65,7 @@ void RegAllocBase::init(VirtRegMap &vrm, LiveIntervals &lis,
Matrix = &mat;
MRI->freezeReservedRegs();
RegClassInfo.runOnMachineFunction(vrm.getMachineFunction());
+ FailedVRegs.clear();
}
// Visit all the live registers. If they are already assigned to a physical
@@ -128,6 +129,7 @@ void RegAllocBase::allocatePhysRegs() {
// Keep going after reporting the error.
VRM->assignVirt2Phys(VirtReg->reg(), AvailablePhysReg);
+ FailedVRegs.insert(VirtReg->reg());
} else if (AvailablePhysReg)
Matrix->assign(*VirtReg, AvailablePhysReg);
@@ -161,6 +163,60 @@ void RegAllocBase::postOptimization() {
DeadRemats.clear();
}
+void RegAllocBase::cleanupFailedVRegs() {
+ SmallSet<Register, 8> JunkRegs;
+
+ for (Register FailedReg : FailedVRegs) {
+ JunkRegs.insert(FailedReg);
+
+ MCRegister PhysReg = VRM->getPhys(FailedReg);
+ LiveInterval &FailedInterval = LIS->getInterval(FailedReg);
+
+ // The liveness information for the failed register and anything interfering
+ // with the physical register we arbitrarily chose is junk and needs to be
+ // deleted.
+ for (MCRegUnitIterator Units(PhysReg, TRI); Units.isValid(); ++Units) {
+ LiveIntervalUnion::Query &Q = Matrix->query(FailedInterval, *Units);
+ for (const LiveInterval *InterferingReg : Q.interferingVRegs())
+ JunkRegs.insert(InterferingReg->reg());
+ LIS->removeRegUnit(*Units);
+ }
+ }
+
+ for (Register JunkReg : JunkRegs) {
+ MCRegister PhysReg = VRM->getPhys(JunkReg);
+ // We still should produce valid IR. Kill all the uses and reduce the live
+ // ranges so that we don't think it's possible to introduce kill flags
+ // later which will fail the verifier.
+ for (MachineOperand &MO : MRI->reg_operands(JunkReg)) {
+ if (MO.readsReg())
+ MO.setIsUndef(true);
+ }
+
+ // The liveness of the assigned physical register is also now unreliable.
+ for (MCRegAliasIterator Aliases(PhysReg, TRI, true); Aliases.isValid();
+ ++Aliases) {
+ for (MachineOperand &MO : MRI->reg_operands(*Aliases)) {
+ if (MO.readsReg())
+ MO.setIsUndef(true);
+ }
+ }
+
+ LiveInterval &JunkLI = LIS->getInterval(JunkReg);
+ if (LIS->shrinkToUses(&JunkLI)) {
+ SmallVector<LiveInterval *, 8> SplitLIs;
+ LIS->splitSeparateComponents(JunkLI, SplitLIs);
+
+ VRM->grow();
+ Register Original = VRM->getOriginal(JunkReg);
+ for (LiveInterval *SplitLI : SplitLIs) {
+ VRM->setIsSplitFromReg(SplitLI->reg(), Original);
+ VRM->assignVirt2Phys(SplitLI->reg(), PhysReg);
+ }
+ }
+ }
+}
+
void RegAllocBase::enqueue(const LiveInterval *LI) {
const Register Reg = LI->reg();
diff --git a/llvm/lib/CodeGen/RegAllocBase.h b/llvm/lib/CodeGen/RegAllocBase.h
index 5bd52da61f2dc..1fdbab694bb0e 100644
--- a/llvm/lib/CodeGen/RegAllocBase.h
+++ b/llvm/lib/CodeGen/RegAllocBase.h
@@ -37,6 +37,7 @@
#define LLVM_LIB_CODEGEN_REGALLOCBASE_H
#include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/ADT/SmallSet.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/RegAllocCommon.h"
#include "llvm/CodeGen/RegisterClassInfo.h"
@@ -81,6 +82,7 @@ class RegAllocBase {
/// always available for the remat of all the siblings of the original reg.
SmallPtrSet<MachineInstr *, 32> DeadRemats;
+ SmallSet<Register, 2> FailedVRegs;
RegAllocBase(const RegAllocFilterFunc F = nullptr)
: shouldAllocateRegisterImpl(F) {}
@@ -104,6 +106,10 @@ class RegAllocBase {
// rematerialization.
virtual void postOptimization();
+ /// Perform cleanups on registers that failed to allocate. This hacks on the
+ /// liveness in order to avoid spurious verifier errors in later passes.
+ void cleanupFailedVRegs();
+
// Get a temporary reference to a Spiller instance.
virtual Spiller &spiller() = 0;
diff --git a/llvm/lib/CodeGen/RegAllocBasic.cpp b/llvm/lib/CodeGen/RegAllocBasic.cpp
index 51e047b2fa3f0..d240bf916ac05 100644
--- a/llvm/lib/CodeGen/RegAllocBasic.cpp
+++ b/llvm/lib/CodeGen/RegAllocBasic.cpp
@@ -329,6 +329,7 @@ bool RABasic::runOnMachineFunction(MachineFunction &mf) {
allocatePhysRegs();
postOptimization();
+ cleanupFailedVRegs();
// Diagnostic output before rewriting
LLVM_DEBUG(dbgs() << "Post alloc VirtRegMap:\n" << *VRM << "\n");
diff --git a/llvm/lib/CodeGen/RegAllocGreedy.cpp b/llvm/lib/CodeGen/RegAllocGreedy.cpp
index f1e734dd2f933..74a363b5bc4b5 100644
--- a/llvm/lib/CodeGen/RegAllocGreedy.cpp
+++ b/llvm/lib/CodeGen/RegAllocGreedy.cpp
@@ -2795,6 +2795,7 @@ bool RAGreedy::runOnMachineFunction(MachineFunction &mf) {
if (VerifyEnabled)
MF->verify(this, "Before post optimization", &errs());
postOptimization();
+ cleanupFailedVRegs();
reportStats();
releaseMemory();
diff --git a/llvm/test/CodeGen/AMDGPU/illegal-eviction-assert.mir b/llvm/test/CodeGen/AMDGPU/illegal-eviction-assert.mir
index 84ade2687f4ba..e583b168c15f7 100644
--- a/llvm/test/CodeGen/AMDGPU/illegal-eviction-assert.mir
+++ b/llvm/test/CodeGen/AMDGPU/illegal-eviction-assert.mir
@@ -13,12 +13,12 @@
ret void
}
- attributes #0 = { "amdgpu-waves-per-eu"="8,8" }
+ attributes #0 = { "amdgpu-waves-per-eu"="8,8" }
...
-# CHECK: S_NOP 0, implicit-def $vgpr4_vgpr5_vgpr6_vgpr7_vgpr8_vgpr9_vgpr10_vgpr11_vgpr12_vgpr13_vgpr14_vgpr15_vgpr16_vgpr17_vgpr18_vgpr19, implicit-def $vgpr20_vgpr21_vgpr22_vgpr23_vgpr24_vgpr25_vgpr26_vgpr27, implicit-def $vgpr0_vgpr1_vgpr2_vgpr3, implicit-def $vgpr28_vgpr29_vgpr30_vgpr31, implicit-def $vgpr0_vgpr1_vgpr2_vgpr3
-# CHECK: S_NOP 0, implicit killed undef $vgpr4_vgpr5_vgpr6_vgpr7_vgpr8_vgpr9_vgpr10_vgpr11_vgpr12_vgpr13_vgpr14_vgpr15_vgpr16_vgpr17_vgpr18_vgpr19, implicit killed undef $vgpr20_vgpr21_vgpr22_vgpr23_vgpr24_vgpr25_vgpr26_vgpr27, implicit killed undef $vgpr0_vgpr1_vgpr2_vgpr3, implicit killed undef $vgpr28_vgpr29_vgpr30_vgpr31, implicit killed undef $vgpr0_vgpr1_vgpr2_vgpr3
+# CHECK: S_NOP 0, implicit-def $vgpr4_vgpr5_vgpr6_vgpr7_vgpr8_vgpr9_vgpr10_vgpr11_vgpr12_vgpr13_vgpr14_vgpr15_vgpr16_vgpr17_vgpr18_vgpr19, implicit-def $vgpr20_vgpr21_vgpr22_vgpr23_vgpr24_vgpr25_vgpr26_vgpr27, implicit-def dead $vgpr0_vgpr1_vgpr2_vgpr3, implicit-def $vgpr28_vgpr29_vgpr30_vgpr31, implicit-def dead $vgpr0_vgpr1_vgpr2_vgpr3
+# CHECK: S_NOP 0, implicit killed undef $vgpr4_vgpr5_vgpr6_vgpr7_vgpr8_vgpr9_vgpr10_vgpr11_vgpr12_vgpr13_vgpr14_vgpr15_vgpr16_vgpr17_vgpr18_vgpr19, implicit killed undef $vgpr20_vgpr21_vgpr22_vgpr23_vgpr24_vgpr25_vgpr26_vgpr27, implicit undef $vgpr0_vgpr1_vgpr2_vgpr3, implicit killed undef $vgpr28_vgpr29_vgpr30_vgpr31, implicit undef $vgpr0_vgpr1_vgpr2_vgpr3
---
name: foo
diff --git a/llvm/test/CodeGen/AMDGPU/inflated-reg-class-snippet-copy-use-after-free.mir b/llvm/test/CodeGen/AMDGPU/inflated-reg-class-snippet-copy-use-after-free.mir
index 503f27edf70df..6d63a4a1cc0ab 100644
--- a/llvm/test/CodeGen/AMDGPU/inflated-reg-class-snippet-copy-use-after-free.mir
+++ b/llvm/test/CodeGen/AMDGPU/inflated-reg-class-snippet-copy-use-after-free.mir
@@ -27,10 +27,10 @@
# CHECK-LABEL: name: inflated_reg_class_copy_use_after_free
# CHECK: S_NOP 0, implicit-def [[ORIG_REG:%[0-9]+]].sub0_sub1_sub2_sub3
# CHECK-NEXT: SI_SPILL_AV512_SAVE [[ORIG_REG]], %stack.0, $sgpr32, 0, implicit $exec :: (store (s512) into %stack.0, align 4, addrspace 5)
-# CHECK-NEXT: [[RESTORE0:%[0-9]+]]:vreg_512_align2 = SI_SPILL_V512_RESTORE %stack.0, $sgpr32, 0, implicit $exec :: (load (s512) from %stack.0, align 4, addrspace 5)
-# CHECK-NEXT: early-clobber [[MFMA0:%[0-9]+]]:vreg_512_align2 = V_MFMA_F32_16X16X1F32_vgprcd_e64 undef %3:vgpr_32, undef %3:vgpr_32, [[RESTORE0]], 0, 0, 0, implicit $mode, implicit $exec, implicit $mode, implicit $exec
-# CHECK-NEXT: undef [[SPLIT0:%[0-9]+]].sub2_sub3:av_512_align2 = COPY [[MFMA0]].sub2_sub3 {
-# CHECK-NEXT: internal [[SPLIT0]].sub0:av_512_align2 = COPY [[MFMA0]].sub0
+# CHECK-NEXT: dead [[RESTORE0:%[0-9]+]]:vreg_512_align2 = SI_SPILL_V512_RESTORE %stack.0, $sgpr32, 0, implicit $exec :: (load (s512) from %stack.0, align 4, addrspace 5)
+# CHECK-NEXT: dead early-clobber [[MFMA0:%[0-9]+]]:vreg_512_align2 = V_MFMA_F32_16X16X1F32_vgprcd_e64 undef %3:vgpr_32, undef %3:vgpr_32, undef [[RESTORE0]], 0, 0, 0, implicit $mode, implicit $exec, implicit $mode, implicit $exec
+# CHECK-NEXT: undef [[SPLIT0:%[0-9]+]].sub2_sub3:av_512_align2 = COPY undef [[MFMA0]].sub2_sub3 {
+# CHECK-NEXT: internal [[SPLIT0]].sub0:av_512_align2 = COPY undef [[MFMA0]].sub0
# CHECK-NEXT: }
# CHECK-NEXT: undef [[SPLIT1:%[0-9]+]].sub2_sub3:av_512_align2 = COPY [[SPLIT0]].sub2_sub3 {
# CHECK-NEXT: internal [[SPLIT1]].sub0:av_512_align2 = COPY [[SPLIT0]].sub0
@@ -118,10 +118,10 @@ body: |
# CHECK-LABEL: name: inflated_reg_class_copy_use_after_free_lane_subset
# CHECK: S_NOP 0, implicit-def [[ORIG_REG:%[0-9]+]].sub0_sub1_sub2_sub3
# CHECK-NEXT: SI_SPILL_AV512_SAVE [[ORIG_REG]], %stack.0, $sgpr32, 0, implicit $exec :: (store (s512) into %stack.0, align 4, addrspace 5)
-# CHECK-NEXT: [[RESTORE_0:%[0-9]+]]:av_512_align2 = SI_SPILL_AV512_RESTORE %stack.0, $sgpr32, 0, implicit $exec :: (load (s512) from %stack.0, align 4, addrspace 5)
-# CHECK-NEXT: S_NOP 0, implicit-def early-clobber [[REG1:%[0-9]+]], implicit [[RESTORE_0]].sub0_sub1_sub2_sub3, implicit [[RESTORE_0]].sub4_sub5_sub6_sub7
-# CHECK-NEXT: undef [[SPLIT0:%[0-9]+]].sub2_sub3:av_512_align2 = COPY [[REG1]].sub2_sub3 {
-# CHECK-NEXT: internal [[SPLIT0]].sub0:av_512_align2 = COPY [[REG1]].sub0
+# CHECK-NEXT: dead [[RESTORE_0:%[0-9]+]]:av_512_align2 = SI_SPILL_AV512_RESTORE %stack.0, $sgpr32, 0, implicit $exec :: (load (s512) from %stack.0, align 4, addrspace 5)
+# CHECK-NEXT: S_NOP 0, implicit-def dead early-clobber [[REG1:%[0-9]+]], implicit undef [[RESTORE_0]].sub0_sub1_sub2_sub3, implicit undef [[RESTORE_0]].sub4_sub5_sub6_sub7
+# CHECK-NEXT: undef [[SPLIT0:%[0-9]+]].sub2_sub3:av_512_align2 = COPY undef [[REG1]].sub2_sub3 {
+# CHECK-NEXT: internal [[SPLIT0]].sub0:av_512_align2 = COPY undef [[REG1]].sub0
# CHECK-NEXT: }
# CHECK-NEXT: undef [[SPLIT1:%[0-9]+]].sub2_sub3:av_512_align2 = COPY [[SPLIT0]].sub2_sub3 {
# CHECK-NEXT: internal [[SPLIT1]].sub0:av_512_align2 = COPY [[SPLIT0]].sub0
diff --git a/llvm/test/CodeGen/AMDGPU/issue48473.mir b/llvm/test/CodeGen/AMDGPU/issue48473.mir
index ada15be594891..c5cb1445adca0 100644
--- a/llvm/test/CodeGen/AMDGPU/issue48473.mir
+++ b/llvm/test/CodeGen/AMDGPU/issue48473.mir
@@ -43,7 +43,7 @@
# %25 to $sgpr60_sgpr61_sgpr62_sgpr63_sgpr64_sgpr65_sgpr66_sgpr67
# CHECK-LABEL: name: issue48473
-# CHECK: S_NOP 0, implicit killed undef $sgpr0_sgpr1_sgpr2_sgpr3, implicit killed undef $sgpr12_sgpr13_sgpr14_sgpr15, implicit killed undef $sgpr16_sgpr17_sgpr18_sgpr19_sgpr20_sgpr21_sgpr22_sgpr23, implicit killed undef $sgpr24_sgpr25_sgpr26_sgpr27_sgpr28_sgpr29_sgpr30_sgpr31, implicit killed undef $sgpr84_sgpr85_sgpr86_sgpr87, implicit killed undef $sgpr36_sgpr37_sgpr38_sgpr39_sgpr40_sgpr41_sgpr42_sgpr43, implicit killed undef $sgpr4_sgpr5_sgpr6_sgpr7, implicit killed undef $sgpr44_sgpr45_sgpr46_sgpr47_sgpr48_sgpr49_sgpr50_sgpr51, implicit killed undef $sgpr88_sgpr89_sgpr90_sgpr91, implicit killed undef $sgpr76_sgpr77_sgpr78_sgpr79_sgpr80_sgpr81_sgpr82_sgpr83, implicit killed undef $sgpr0_sgpr1_sgpr2_sgpr3, implicit killed undef $sgpr52_sgpr53_sgpr54_sgpr55_sgpr56_sgpr57_sgpr58_sgpr59, implicit killed undef $sgpr92_sgpr93_sgpr94_sgpr95, implicit killed undef $sgpr68_sgpr69_sgpr70_sgpr71_sgpr72_sgpr73_sgpr74_sgpr75, implicit undef $sgpr68_sgpr69_sgpr70_sgpr71_sgpr72_sgpr73_sgpr74_sgpr75, implicit killed undef $sgpr96_sgpr97_sgpr98_sgpr99, implicit killed undef $sgpr8_sgpr9_sgpr10_sgpr11, implicit killed undef $sgpr60_sgpr61_sgpr62_sgpr63_sgpr64_sgpr65_sgpr66_sgpr67
+# CHECK: S_NOP 0, implicit undef $sgpr0_sgpr1_sgpr2_sgpr3, implicit killed undef $sgpr12_sgpr13_sgpr14_sgpr15, implicit killed undef $sgpr16_sgpr17_sgpr18_sgpr19_sgpr20_sgpr21_sgpr22_sgpr23, implicit killed undef $sgpr24_sgpr25_sgpr26_sgpr27_sgpr28_sgpr29_sgpr30_sgpr31, implicit killed undef $sgpr84_sgpr85_sgpr86_sgpr87, implicit killed undef $sgpr36_sgpr37_sgpr38_sgpr39_sgpr40_sgpr41_sgpr42_sgpr43, implicit killed undef $sgpr4_sgpr5_sgpr6_sgpr7, implicit killed undef $sgpr44_sgpr45_sgpr46_sgpr47_sgpr48_sgpr49_sgpr50_sgpr51, implicit killed undef $sgpr88_sgpr89_sgpr90_sgpr91, implicit killed undef $sgpr76_sgpr77_sgpr78_sgpr79_sgpr80_sgpr81_sgpr82_sgpr83, implicit undef $sgpr0_sgpr1_sgpr2_sgpr3, implicit killed undef $sgpr52_sgpr53_sgpr54_sgpr55_sgpr56_sgpr57_sgpr58_sgpr59, implicit killed undef $sgpr92_sgpr93_sgpr94_sgpr95, implicit killed undef $sgpr68_sgpr69_sgpr70_sgpr71_sgpr72_sgpr73_sgpr74_sgpr75, implicit undef $sgpr68_sgpr69_sgpr70_sgpr71_sgpr72_sgpr73_sgpr74_sgpr75, implicit killed undef $sgpr96_sgpr97_sgpr98_sgpr99, implicit killed undef $sgpr8_sgpr9_sgpr10_sgpr11, implicit killed undef $sgpr60_sgpr61_sgpr62_sgpr63_sgpr64_sgpr65_sgpr66_sgpr67
---
name: issue48473
diff --git a/llvm/test/CodeGen/AMDGPU/register-killed-error-after-alloc-failure0.mir b/llvm/test/CodeGen/AMDGPU/register-killed-error-after-alloc-failure0.mir
new file mode 100644
index 0000000000000..e2a839ea9d24e
--- /dev/null
+++ b/llvm/test/CodeGen/AMDGPU/register-killed-error-after-alloc-failure0.mir
@@ -0,0 +1,59 @@
+# RUN: not llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx900 -vgpr-regalloc=basic -sgpr-regalloc=basic -start-before=regallocbasic,0 -stop-after=virtregrewriter,2 -verify-regalloc -o - %s 2> %t.basic.err | FileCheck -check-prefix=BASIC %s
+# RUN: not llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx900 -start-before=greedy,0 -stop-after=virtregrewriter,2 -verify-regalloc -o - %s 2> %t.greedy.err | FileCheck -check-prefix=GREEDY %s
+
+# RUN: FileCheck -check-prefix=ERR -implicit-check-not=error %s < %t.basic.err
+# RUN: FileCheck -check-prefix=ERR -implicit-check-not=error %s < %t.greedy.err
+
+# This testcase must fail register allocation. It should also not
+# produce a verifier error after doing so. Previously, it would not
+# properly update the liveness for the dummy selected register. As a
+# result, VirtRegRewriter would incorrectly add kill flags which
+# combined with other uses of the physical register produced a
+# verifier error.
+
+# ERR: error: <unknown>:0:0: ran out of registers during register allocation
+
+# GREEDY: SI_SPILL_V256_SAVE undef $vgpr0_vgpr1_vgpr2_vgpr3_vgpr4_vgpr5_vgpr6_vgpr7
+# GREEDY-NEXT: SI_SPILL_V512_SAVE undef $vgpr4_vgpr5_vgpr6_vgpr7_vgpr8_vgpr9_vgpr10_vgpr11_vgpr12_vgpr13_vgpr14_vgpr15_vgpr16_vgpr17_vgpr18_vgpr19
+# GREEDY-NEXT: SI_SPILL_V128_SAVE undef $vgpr0_vgpr1_vgpr2_vgpr3
+
+# GREEDY: dead $vgpr4_vgpr5_vgpr6_vgpr7_vgpr8_vgpr9_vgpr10_vgpr11_vgpr12_vgpr13_vgpr14_vgpr15_vgpr16_vgpr17_vgpr18_vgpr19 = SI_SPILL_V512_RESTORE
+# GREEDY: dead $vgpr0_vgpr1_vgpr2_vgpr3_vgpr4_vgpr5_vgpr6_vgpr7 = SI_SPILL_V256_RESTORE
+# GREEDY: S_NOP 0, implicit undef $vgpr4_vgpr5_vgpr6_vgpr7_vgpr8_vgpr9_vgpr10_vgpr11_vgpr12_vgpr13_vgpr14_vgpr15_vgpr16_vgpr17_vgpr18_vgpr19, implicit undef $vgpr0_vgpr1_vgpr2_vgpr3_vgpr4_vgpr5_vgpr6_vgpr7, implicit undef $vgpr0_vgpr1_vgpr2_vgpr3
+# GREEDY: S_NOP 0, implicit killed undef $vgpr20_vgpr21
+
+
+# BASIC: SI_SPILL_V128_SAVE undef $vgpr0_vgpr1_vgpr2_vgpr3
+# BASIC: SI_SPILL_V256_SAVE killed undef $vgpr16_vgpr17_vgpr18_vgpr19_vgpr20_vgpr21_vgpr22_vgpr23
+# BASIC: SI_SPILL_V512_SAVE undef $vgpr0_vgpr1_vgpr2_vgpr3_vgpr4_vgpr5_vgpr6_vgpr7_vgpr8_vgpr9_vgpr10_vgpr11_vgpr12_vgpr13_vgpr14_vgpr15
+# BASIC: SI_SPILL_V64_SAVE killed undef $vgpr0_vgpr1, %stack.{{[0-9]+}}, $sgpr32, 0, implicit $exec :: (store (s64) into %stack.{{[0-9]+}}, align 4, addrspace 5)
+# BASIC: dead $vgpr0_vgpr1_vgpr2_vgpr3_vgpr4_vgpr5_vgpr6_vgpr7_vgpr8_vgpr9_vgpr10_vgpr11_vgpr12_vgpr13_vgpr14_vgpr15 = SI_SPILL_V512_RESTORE
+# BASIC: $vgpr16_vgpr17_vgpr18_vgpr19_vgpr20_vgpr21_vgpr22_vgpr23 = SI_SPILL_V256_RESTORE
+# BASIC: dead $vgpr0_vgpr1_vgpr2_vgpr3 = SI_SPILL_V128_RESTORE
+# BASIC: S_NOP 0, implicit undef $vgpr0_vgpr1_vgpr2_vgpr3_vgpr4_vgpr5_vgpr6_vgpr7_vgpr8_vgpr9_vgpr10_vgpr11_vgpr12_vgpr13_vgpr14_vgpr15, implicit killed undef $vgpr16_vgpr17_vgpr18_vgpr19_vgpr20_vgpr21_vgpr22_vgpr23, implicit undef $vgpr0_vgpr1_vgpr2_vgpr3
+# BASIC: $vgpr0_vgpr1 = SI_SPILL_V64_RESTORE
+
+--- |
+ define void @killed_reg_after_regalloc_failure() #0 {
+ ret void
+ }
+
+ attributes #0 = { "amdgpu-waves-per-eu"="10,10" }
+
+...
+---
+name: killed_reg_after_regalloc_failure
+tracksRegLiveness: true
+machineFunctionInfo:
+ scratchRSrcReg: '$sgpr0_sgpr1_sgpr2_sgpr3'
+ frameOffsetReg: '$sgpr33'
+ stackPtrOffsetReg: '$sgpr32'
+body: |
+ bb.0:
+ S_NOP 0, implicit-def %0:vreg_512, implicit-def %1:vreg_256, implicit-def %2:vreg_128
+ S_NOP 0, implicit-def %3:vreg_64
+ S_NOP 0, implicit %0, implicit %1, implicit %2
+ S_NOP 0, implicit %3
+ S_ENDPGM 0
+
+...
diff --git a/llvm/test/CodeGen/AMDGPU/register-killed-error-after-alloc-failure1.ll b/llvm/test/CodeGen/AMDGPU/register-killed-error-after-alloc-failure1.ll
new file mode 100644
index 0000000000000..5e466a9470fc5
--- /dev/null
+++ b/llvm/test/CodeGen/AMDGPU/register-killed-error-after-alloc-failure1.ll
@@ -0,0 +1,30 @@
+; RUN: not llc -mtriple=amdgcn -mcpu=gfx908 -verify-machineinstrs -filetype=null %s 2>&1 | FileCheck -check-prefix=ERR -implicit-check-not=error %s
+
+; ERR: error: inline assembly requires more registers than available
+; ERR-NOT: ERROR
+; ERR-NOT: Bad machine code
+
+; This test requires respecting undef on the spill source operand when
+; expanding the pseudos to avoid all verifier errors
+
+%asm.output = type { <16 x i32>, <8 x i32>, <4 x i32>, <3 x i32>, <3 x i32> }
+
+define void @foo(<32 x i32> addrspace(1)* %arg) #0 {
+ %agpr0 = call i32 asm sideeffect "; def $0","=${a0}"()
+ %asm = call %asm.output asm sideeffect "; def $0 $1 $2 $3 $4","=v,=v,=v,=v,=v"()
+ %vgpr0 = extractvalue %asm.output %asm, 0
+ %vgpr1 = extractvalue %asm.output %asm, 1
+ %vgpr2 = extractvalue %asm.output %asm, 2
+ %vgpr3 = extractvalue %asm.output %asm, 3
+ %vgpr4 = extractvalue %asm.output %asm, 4
+ call void asm sideeffect "; clobber", "~{a[0:31]},~{v[0:31]}"()
+ call void asm sideeffect "; use $0","v"(<16 x i32> %vgpr0)
+ call void asm sideeffect "; use $0","v"(<8 x i32> %vgpr1)
+ call void asm sideeffect "; use $0","v"(<4 x i32> %vgpr2)
+ call void asm sideeffect "; use $0","v"(<3 x i32> %vgpr3)
+ call void asm sideeffect "; use $0","v"(<3 x i32> %vgpr4)
+ call void asm sideeffect "; use $0","{a1}"(i32 %agpr0)
+ ret void
+}
+
+attributes #0 = { "amdgpu-waves-per-eu"="8,8" }
diff --git a/llvm/test/CodeGen/AMDGPU/remaining-virtual-register-operands.ll b/llvm/test/CodeGen/AMDGPU/remaining-virtual-register-operands.ll
index a9654be075692..9279b44edac75 100644
--- a/llvm/test/CodeGen/AMDGPU/remaining-virtual-register-operands.ll
+++ b/llvm/test/CodeGen/AMDGPU/remaining-virtual-register-operands.ll
@@ -1,4 +1,4 @@
-; RUN: not llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx908 -verify-machineinstrs < %s 2>&1 | FileCheck %s
+; RUN: not llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx908 -verify-machineinstrs -filetype=null %s 2>&1 | FileCheck -implicit-check-not=error %s
; This testcase fails register allocation at the same time it performs
; virtual register splitting (by introducing VGPR to AGPR copies). We
|
You can test this locally with the following command:git diff -U0 --pickaxe-regex -S '([^a-zA-Z0-9#_-]undef[^a-zA-Z0-9_-]|UndefValue::get)' 3f648992bf317a3496c4d137374d2c1532423d1c 7319a933eb97fe444a20d2527386d0a71f626621 llvm/test/CodeGen/AMDGPU/register-killed-error-after-alloc-failure1.ll llvm/lib/CodeGen/RegAllocBase.cpp llvm/lib/CodeGen/RegAllocBase.h llvm/lib/CodeGen/RegAllocBasic.cpp llvm/lib/CodeGen/RegAllocGreedy.cpp llvm/test/CodeGen/AMDGPU/remaining-virtual-register-operands.llThe following files introduce new uses of undef:
Undef is now deprecated and should only be used in the rare cases where no replacement is possible. For example, a load of uninitialized memory yields In tests, avoid using For example, this is considered a bad practice: define void @fn() {
...
br i1 undef, ...
}Please use the following instead: define void @fn(i1 %cond) {
...
br i1 %cond, ...
}Please refer to the Undefined Behavior Manual for more information. |
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This reverts commit 0c50054. Reapply with more fixes to avoid expensive_checks failures. Make sure to call splitSeparateComponents after shrinkToUses, and update the VirtRegMap with the split registers. Also set undef on all physical register aliases to the assigned register.
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Reapply "RegAlloc: Fix verifier error after failed allocation (#119690)"
This reverts commit 0c50054.
Reapply with more fixes to avoid expensive_checks failures. Make sure to
call splitSeparateComponents after shrinkToUses, and update the VirtRegMap
with the split registers. Also set undef on all physical register aliases to
the assigned register.
Move physreg handling. Not sure if necessary
Remove intervals from regunits. Not sure if necessary