[GISel] Add narrowScalar/widenScalar support for `G_CONSTANT_FOLD_BARRIER` #93031

dtcxzyw · 2024-05-22T13:42:41Z

Fixes an error that llc fails to legalize G_CONSTANT_FOLD_BARRIER with i16/i128: https://godbolt.org/z/f9n6xM3sv

…RIER`

llvmbot · 2024-05-22T13:43:14Z

@llvm/pr-subscribers-llvm-globalisel

Author: Yingwei Zheng (dtcxzyw)

Changes

Fixes an error that llc fails to legalize G_CONSTANT_FOLD_BARRIER with i16/i128: https://godbolt.org/z/f9n6xM3sv

Full diff: https://github.com/llvm/llvm-project/pull/93031.diff

5 Files Affected:

(modified) llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp (+4-2)
(added) llvm/test/CodeGen/RISCV/GlobalISel/constbarrier-rv32.ll (+60)
(added) llvm/test/CodeGen/RISCV/GlobalISel/constbarrier-rv64.ll (+36)
(modified) llvm/test/CodeGen/RISCV/GlobalISel/legalizer/legalize-constbarrier-rv32.mir (+32)
(modified) llvm/test/CodeGen/RISCV/GlobalISel/legalizer/legalize-constbarrier-rv64.mir (+33)

diff --git a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
index 40507845d8d89..d8b0f52ecf9e3 100644
--- a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
@@ -1296,7 +1296,7 @@ LegalizerHelper::LegalizeResult LegalizerHelper::narrowScalar(MachineInstr &MI,
     MI.eraseFromParent();
     return Legalized;
   }
-
+  case TargetOpcode::G_CONSTANT_FOLD_BARRIER:
   case TargetOpcode::G_FREEZE: {
     if (TypeIdx != 0)
       return UnableToLegalize;
@@ -1310,7 +1310,8 @@ LegalizerHelper::LegalizeResult LegalizerHelper::narrowScalar(MachineInstr &MI,
     SmallVector<Register, 8> Parts;
     for (unsigned i = 0; i < Unmerge->getNumDefs(); ++i) {
       Parts.push_back(
-          MIRBuilder.buildFreeze(NarrowTy, Unmerge.getReg(i)).getReg(0));
+          MIRBuilder.buildInstr(MI.getOpcode(), {NarrowTy}, {Unmerge.getReg(i)})
+              .getReg(0));
     }
 
     MIRBuilder.buildMergeLikeInstr(MI.getOperand(0).getReg(), Parts);
@@ -2515,6 +2516,7 @@ LegalizerHelper::widenScalar(MachineInstr &MI, unsigned TypeIdx, LLT WideTy) {
     return Legalized;
   }
   case TargetOpcode::G_FREEZE:
+  case TargetOpcode::G_CONSTANT_FOLD_BARRIER:
     Observer.changingInstr(MI);
     widenScalarSrc(MI, WideTy, 1, TargetOpcode::G_ANYEXT);
     widenScalarDst(MI, WideTy);
diff --git a/llvm/test/CodeGen/RISCV/GlobalISel/constbarrier-rv32.ll b/llvm/test/CodeGen/RISCV/GlobalISel/constbarrier-rv32.ll
new file mode 100644
index 0000000000000..70d1b25309c84
--- /dev/null
+++ b/llvm/test/CodeGen/RISCV/GlobalISel/constbarrier-rv32.ll
@@ -0,0 +1,60 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 5
+; RUN: llc -mtriple=riscv32 -global-isel -verify-machineinstrs < %s \
+; RUN:   | FileCheck %s --check-prefixes=RV32
+
+define i16 @constant_fold_barrier_i16(i16 %x, i16 %y) {
+; RV32-LABEL: constant_fold_barrier_i16:
+; RV32:       # %bb.0: # %entry
+; RV32-NEXT:    li a1, 1
+; RV32-NEXT:    slli a1, a1, 11
+; RV32-NEXT:    and a0, a0, a1
+; RV32-NEXT:    addi a1, a1, 289
+; RV32-NEXT:    or a0, a0, a1
+; RV32-NEXT:    ret
+entry:
+  %and = and i16 %x, 2048
+  %or = or i16 %and, 2337
+  ret i16 %or
+}
+
+define void @constant_fold_barrier_i128(ptr %p) {
+; RV32-LABEL: constant_fold_barrier_i128:
+; RV32:       # %bb.0: # %entry
+; RV32-NEXT:    li a1, 1
+; RV32-NEXT:    slli a1, a1, 11
+; RV32-NEXT:    lw a2, 0(a0)
+; RV32-NEXT:    lw a3, 4(a0)
+; RV32-NEXT:    lw a4, 8(a0)
+; RV32-NEXT:    lw a5, 12(a0)
+; RV32-NEXT:    and a2, a2, a1
+; RV32-NEXT:    and a3, a3, zero
+; RV32-NEXT:    and a4, a4, zero
+; RV32-NEXT:    and a5, a5, zero
+; RV32-NEXT:    add a2, a2, a1
+; RV32-NEXT:    sltu a1, a2, a1
+; RV32-NEXT:    add a6, a3, zero
+; RV32-NEXT:    sltu a3, a6, a3
+; RV32-NEXT:    add a6, a6, a1
+; RV32-NEXT:    seqz a7, a6
+; RV32-NEXT:    and a1, a7, a1
+; RV32-NEXT:    or a1, a3, a1
+; RV32-NEXT:    add a3, a4, zero
+; RV32-NEXT:    sltu a4, a3, a4
+; RV32-NEXT:    add a3, a3, a1
+; RV32-NEXT:    seqz a7, a3
+; RV32-NEXT:    and a1, a7, a1
+; RV32-NEXT:    or a1, a4, a1
+; RV32-NEXT:    add a5, a5, zero
+; RV32-NEXT:    add a1, a5, a1
+; RV32-NEXT:    sw a2, 0(a0)
+; RV32-NEXT:    sw a6, 4(a0)
+; RV32-NEXT:    sw a3, 8(a0)
+; RV32-NEXT:    sw a1, 12(a0)
+; RV32-NEXT:    ret
+entry:
+  %x = load i128, ptr %p
+  %and = and i128 %x, 2048
+  %add = add i128 %and, 2048
+  store i128 %add, ptr %p
+  ret void
+}
diff --git a/llvm/test/CodeGen/RISCV/GlobalISel/constbarrier-rv64.ll b/llvm/test/CodeGen/RISCV/GlobalISel/constbarrier-rv64.ll
new file mode 100644
index 0000000000000..21d7b1d70714d
--- /dev/null
+++ b/llvm/test/CodeGen/RISCV/GlobalISel/constbarrier-rv64.ll
@@ -0,0 +1,36 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 5
+; RUN: llc -mtriple=riscv64 -global-isel -verify-machineinstrs < %s \
+; RUN:   | FileCheck %s --check-prefixes=RV64
+
+define i16 @constant_fold_barrier_i16(i16 %x, i16 %y) {
+; RV64-LABEL: constant_fold_barrier_i16:
+; RV64:       # %bb.0: # %entry
+; RV64-NEXT:    li a1, 1
+; RV64-NEXT:    slli a1, a1, 11
+; RV64-NEXT:    and a0, a0, a1
+; RV64-NEXT:    addiw a1, a1, 289
+; RV64-NEXT:    or a0, a0, a1
+; RV64-NEXT:    ret
+entry:
+  %and = and i16 %x, 2048
+  %or = or i16 %and, 2337
+  ret i16 %or
+}
+
+define i128 @constant_fold_barrier_i128(i128 %x) {
+; RV64-LABEL: constant_fold_barrier_i128:
+; RV64:       # %bb.0: # %entry
+; RV64-NEXT:    li a2, 1
+; RV64-NEXT:    slli a2, a2, 11
+; RV64-NEXT:    and a0, a0, a2
+; RV64-NEXT:    and a1, a1, zero
+; RV64-NEXT:    add a0, a0, a2
+; RV64-NEXT:    sltu a2, a0, a2
+; RV64-NEXT:    add a1, a1, zero
+; RV64-NEXT:    add a1, a1, a2
+; RV64-NEXT:    ret
+entry:
+  %and = and i128 %x, 2048
+  %add = add i128 %and, 2048
+  ret i128 %add
+}
diff --git a/llvm/test/CodeGen/RISCV/GlobalISel/legalizer/legalize-constbarrier-rv32.mir b/llvm/test/CodeGen/RISCV/GlobalISel/legalizer/legalize-constbarrier-rv32.mir
index 6b1fc2042e2b8..bbe8ef4b092d3 100644
--- a/llvm/test/CodeGen/RISCV/GlobalISel/legalizer/legalize-constbarrier-rv32.mir
+++ b/llvm/test/CodeGen/RISCV/GlobalISel/legalizer/legalize-constbarrier-rv32.mir
@@ -14,6 +14,38 @@ body:             |
     $x10 = COPY %2(s32)
     PseudoRET implicit $x10
 
+...
+---
+name:            constbarrier_i16
+body:             |
+  bb.0.entry:
+    ; CHECK-LABEL: name: constbarrier_i16
+    ; CHECK: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 2048
+    ; CHECK-NEXT: [[CONSTANT_FOLD_BARRIER:%[0-9]+]]:_(s32) = G_CONSTANT_FOLD_BARRIER [[C]]
+    ; CHECK-NEXT: $x10 = COPY [[CONSTANT_FOLD_BARRIER]](s32)
+    ; CHECK-NEXT: PseudoRET implicit $x10
+    %1:_(s16) = G_CONSTANT i16 2048
+    %2:_(s16) = G_CONSTANT_FOLD_BARRIER %1
+    %3:_(s32) = G_ANYEXT %2(s16)
+    $x10 = COPY %3(s32)
+    PseudoRET implicit $x10
+
+...
+---
+name:            constbarrier_i128
+body:             |
+  bb.0.entry:
+    ; CHECK-LABEL: name: constbarrier_i128
+    ; CHECK: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 2048
+    ; CHECK-NEXT: [[CONSTANT_FOLD_BARRIER:%[0-9]+]]:_(s32) = G_CONSTANT_FOLD_BARRIER [[C]]
+    ; CHECK-NEXT: $x10 = COPY [[CONSTANT_FOLD_BARRIER]](s32)
+    ; CHECK-NEXT: PseudoRET implicit $x10
+    %1:_(s128) = G_CONSTANT i128 2048
+    %2:_(s128) = G_CONSTANT_FOLD_BARRIER %1
+    %3:_(s32) = G_TRUNC %2(s128)
+    $x10 = COPY %3(s32)
+    PseudoRET implicit $x10
+
 ...
 ---
 name:            constbarrier_nxv2i1
diff --git a/llvm/test/CodeGen/RISCV/GlobalISel/legalizer/legalize-constbarrier-rv64.mir b/llvm/test/CodeGen/RISCV/GlobalISel/legalizer/legalize-constbarrier-rv64.mir
index de6a82beee2ab..96b1aa53d46ea 100644
--- a/llvm/test/CodeGen/RISCV/GlobalISel/legalizer/legalize-constbarrier-rv64.mir
+++ b/llvm/test/CodeGen/RISCV/GlobalISel/legalizer/legalize-constbarrier-rv64.mir
@@ -31,6 +31,39 @@ body:             |
     $x10 = COPY %2(s64)
     PseudoRET implicit $x10
 
+...
+---
+name:            constbarrier_i16
+body:             |
+  bb.0.entry:
+    ; CHECK-LABEL: name: constbarrier_i16
+    ; CHECK: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 2048
+    ; CHECK-NEXT: [[CONSTANT_FOLD_BARRIER:%[0-9]+]]:_(s32) = G_CONSTANT_FOLD_BARRIER [[C]]
+    ; CHECK-NEXT: [[ANYEXT:%[0-9]+]]:_(s64) = G_ANYEXT [[CONSTANT_FOLD_BARRIER]](s32)
+    ; CHECK-NEXT: $x10 = COPY [[ANYEXT]](s64)
+    ; CHECK-NEXT: PseudoRET implicit $x10
+    %1:_(s16) = G_CONSTANT i16 2048
+    %2:_(s16) = G_CONSTANT_FOLD_BARRIER %1
+    %3:_(s64) = G_ANYEXT %2(s16)
+    $x10 = COPY %3(s64)
+    PseudoRET implicit $x10
+
+...
+---
+name:            constbarrier_i128
+body:             |
+  bb.0.entry:
+    ; CHECK-LABEL: name: constbarrier_i128
+    ; CHECK: [[C:%[0-9]+]]:_(s64) = G_CONSTANT i64 2048
+    ; CHECK-NEXT: [[CONSTANT_FOLD_BARRIER:%[0-9]+]]:_(s64) = G_CONSTANT_FOLD_BARRIER [[C]]
+    ; CHECK-NEXT: $x10 = COPY [[CONSTANT_FOLD_BARRIER]](s64)
+    ; CHECK-NEXT: PseudoRET implicit $x10
+    %1:_(s128) = G_CONSTANT i128 2048
+    %2:_(s128) = G_CONSTANT_FOLD_BARRIER %1
+    %3:_(s64) = G_TRUNC %2(s128)
+    $x10 = COPY %3(s64)
+    PseudoRET implicit $x10
+
 ...
 ---
 name:            constbarrier_nxv2i1

…RIER` (llvm#93031) Fixes an error that llc fails to legalize `G_CONSTANT_FOLD_BARRIER` with i16/i128: https://godbolt.org/z/f9n6xM3sv

[GISel] Add narrowScalar/widenScalar support for `G_CONSTANT_FOLD_BAR…

5d953fd

…RIER`

dtcxzyw requested review from arsenm, michaelmaitland, tschuett and topperc May 22, 2024 13:42

llvmbot added the llvm:globalisel label May 22, 2024

arsenm approved these changes May 22, 2024

View reviewed changes

dtcxzyw merged commit 821bcba into llvm:main May 22, 2024
5 of 6 checks passed

dtcxzyw deleted the gisel-constbarrier-narrow-widen branch May 22, 2024 15:35

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[GISel] Add narrowScalar/widenScalar support for `G_CONSTANT_FOLD_BARRIER` #93031

[GISel] Add narrowScalar/widenScalar support for `G_CONSTANT_FOLD_BARRIER` #93031