[llvm] 7df3544 - [GlobalISel] Fix assertion failures after "GlobalISel: Return APInt from getConstantVRegVal" landed.

[Amara Emerson via llvm-commits]

Author: Amara Emerson
Date: 2020-12-26T23:51:44-08:00
New Revision: 7df3544e80fb40c742707613cd39ca77f7fea558

URL: https://github.com/llvm/llvm-project/commit/7df3544e80fb40c742707613cd39ca77f7fea558
DIFF: https://github.com/llvm/llvm-project/commit/7df3544e80fb40c742707613cd39ca77f7fea558.diff

LOG: [GlobalISel] Fix assertion failures after "GlobalISel: Return APInt from getConstantVRegVal" landed.

APInt binary ops don't promote types but instead assert, which a combine was
relying on.

Added: 
    llvm/test/CodeGen/AArch64/GlobalISel/combine-shift-immed-mismatch-crash.mir

Modified: 
    llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp b/llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp
index 90b1dcea2648..abc23da3d418 100644
--- a/llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp
@@ -1570,7 +1570,8 @@ bool CombinerHelper::matchShiftImmedChain(MachineInstr &MI,
     return false;
 
   // Pass the combined immediate to the apply function.
-  MatchInfo.Imm = (MaybeImmVal->Value + MaybeImm2Val->Value).getSExtValue();
+  MatchInfo.Imm =
+      (MaybeImmVal->Value.getSExtValue() + MaybeImm2Val->Value).getSExtValue();
   MatchInfo.Reg = Base;
 
   // There is no simple replacement for a saturating unsigned left shift that

diff  --git a/llvm/test/CodeGen/AArch64/GlobalISel/combine-shift-immed-mismatch-crash.mir b/llvm/test/CodeGen/AArch64/GlobalISel/combine-shift-immed-mismatch-crash.mir
new file mode 100644
index 000000000000..481c71fbed60
--- /dev/null
+++ b/llvm/test/CodeGen/AArch64/GlobalISel/combine-shift-immed-mismatch-crash.mir
@@ -0,0 +1,58 @@
+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
+# RUN: llc -run-pass=aarch64-prelegalizer-combiner -verify-machineinstrs -mtriple aarch64-unknown-unknown %s -o - | FileCheck %s
+---
+name:            shift_immed_chain_mismatch_size_crash
+alignment:       4
+tracksRegLiveness: true
+liveins:
+  - { reg: '$x0' }
+body:             |
+  ; CHECK-LABEL: name: shift_immed_chain_mismatch_size_crash
+  ; CHECK: bb.0:
+  ; CHECK:   successors: %bb.1(0x40000000), %bb.2(0x40000000)
+  ; CHECK:   liveins: $x0
+  ; CHECK:   [[DEF:%[0-9]+]]:_(p0) = G_IMPLICIT_DEF
+  ; CHECK:   [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 16
+  ; CHECK:   [[C1:%[0-9]+]]:_(s32) = G_CONSTANT i32 9
+  ; CHECK:   [[DEF1:%[0-9]+]]:_(s1) = G_IMPLICIT_DEF
+  ; CHECK:   G_BRCOND [[DEF1]](s1), %bb.2
+  ; CHECK:   G_BR %bb.1
+  ; CHECK: bb.1:
+  ; CHECK:   successors:
+  ; CHECK: bb.2:
+  ; CHECK:   [[LOAD:%[0-9]+]]:_(s32) = G_LOAD [[DEF]](p0) :: (load 4 from `i32* undef`, align 8)
+  ; CHECK:   [[MUL:%[0-9]+]]:_(s32) = nsw G_MUL [[C]], [[LOAD]]
+  ; CHECK:   [[MUL1:%[0-9]+]]:_(s32) = nsw G_MUL [[MUL]], [[C1]]
+  ; CHECK:   [[C2:%[0-9]+]]:_(s64) = G_CONSTANT i64 2
+  ; CHECK:   [[SHL:%[0-9]+]]:_(s32) = G_SHL [[MUL1]], [[C2]](s64)
+  ; CHECK:   $w0 = COPY [[SHL]](s32)
+  ; CHECK:   RET_ReallyLR implicit $w0
+  bb.1:
+    liveins: $x0
+
+    %0:_(p0) = COPY $x0
+    %1:_(s1) = G_IMPLICIT_DEF
+    %3:_(p0) = G_IMPLICIT_DEF
+    %4:_(s32) = G_CONSTANT i32 16
+    %6:_(s32) = G_CONSTANT i32 9
+    %8:_(s32) = G_CONSTANT i32 2
+    %11:_(s64) = G_CONSTANT i64 2
+    G_BRCOND %1(s1), %bb.2
+    G_BR %bb.3
+
+  bb.2:
+    successors:
+
+
+  bb.3:
+    %2:_(s32) = G_LOAD %3(p0) :: (load 4 from `i32* undef`, align 8)
+    %5:_(s32) = nsw G_MUL %4, %2
+    %7:_(s32) = nsw G_MUL %5, %6
+    %9:_(s32) = nsw G_MUL %7, %8
+    %10:_(s64) = G_SEXT %9(s32)
+    %12:_(s64) = G_MUL %10, %11
+    %13:_(s32) = G_TRUNC %12(s64)
+    $w0 = COPY %13(s32)
+    RET_ReallyLR implicit $w0
+
+...