[llvm] [Mips] Fix compiler crash when returning fp128 after calling a functi… (PR #117525)

[via llvm-commits]

https://github.com/yingopq created https://github.com/llvm/llvm-project/pull/117525

…on returning { i8, i128 }

>From 3a542dc3f8abbcbb1cfeb71f6f03b5fdfbd3a63c Mon Sep 17 00:00:00 2001
From: Ying Huang <ying.huang at oss.cipunited.com>
Date: Mon, 25 Nov 2024 02:28:07 -0500
Subject: [PATCH] [Mips] Fix compiler crash when returning fp128 after calling
 a function returning { i8, i128 }

---
 llvm/lib/Target/Mips/MipsCallingConv.td |  4 +-
 llvm/test/CodeGen/Mips/mips64-f128.ll   | 55 +++++++++++++++++++++++++
 2 files changed, 57 insertions(+), 2 deletions(-)

diff --git a/llvm/lib/Target/Mips/MipsCallingConv.td b/llvm/lib/Target/Mips/MipsCallingConv.td
index 25384a3fe8de37..f997dcf2ece2e7 100644
--- a/llvm/lib/Target/Mips/MipsCallingConv.td
+++ b/llvm/lib/Target/Mips/MipsCallingConv.td
@@ -207,8 +207,8 @@ def RetCC_MipsN : CallingConv<[
       CCIfType<[i8, i16, i32, i64],
           CCIfInReg<CCPromoteToUpperBitsInType<i64>>>>,
 
-  // i64 are returned in registers V0_64, V1_64
-  CCIfType<[i64], CCAssignToReg<[V0_64, V1_64]>>,
+  // i64 are returned in registers V0_64, V1_64, A0_64
+  CCIfType<[i64], CCAssignToReg<[V0_64, V1_64, A0_64]>>,
 
   // f32 are returned in registers F0, F2
   CCIfType<[f32], CCAssignToReg<[F0, F2]>>,
diff --git a/llvm/test/CodeGen/Mips/mips64-f128.ll b/llvm/test/CodeGen/Mips/mips64-f128.ll
index ac29154579c500..9633cdcd484a73 100644
--- a/llvm/test/CodeGen/Mips/mips64-f128.ll
+++ b/llvm/test/CodeGen/Mips/mips64-f128.ll
@@ -2903,6 +2903,61 @@ entry:
   %cond = select i1 %cmp, fp128 %c, fp128 %d
   ret fp128 %cond
 }
+
+define { i8, i128 } @bar() {
+  ret { i8, i128 } zeroinitializer
+}
+
+define fp128 @call_retFP128() {
+; C_CC_FMT-LABEL: call_retFP128:
+; C_CC_FMT:       # %bb.0: # %entry
+; C_CC_FMT-NEXT:    daddiu $sp, $sp, -16
+; C_CC_FMT-NEXT:    .cfi_def_cfa_offset 16
+; C_CC_FMT-NEXT:    sd $ra, 8($sp) # 8-byte Folded Spill
+; C_CC_FMT-NEXT:    sd $gp, 0($sp) # 8-byte Folded Spill
+; C_CC_FMT-NEXT:    .cfi_offset 31, -8
+; C_CC_FMT-NEXT:    .cfi_offset 28, -16
+; C_CC_FMT-NEXT:    lui $1, %hi(%neg(%gp_rel(call_retFP128)))
+; C_CC_FMT-NEXT:    daddu $1, $1, $25
+; C_CC_FMT-NEXT:    daddiu $gp, $1, %lo(%neg(%gp_rel(call_retFP128)))
+; C_CC_FMT-NEXT:    ld $25, %call16(bar)($gp)
+; C_CC_FMT-NEXT:    .reloc .Ltmp51, R_MIPS_JALR, bar
+; C_CC_FMT-NEXT:  .Ltmp51:
+; C_CC_FMT-NEXT:    jalr $25
+; C_CC_FMT-NEXT:    nop
+; C_CC_FMT-NEXT:    daddiu $2, $zero, 0
+; C_CC_FMT-NEXT:    daddiu $4, $zero, 0
+; C_CC_FMT-NEXT:    ld $gp, 0($sp) # 8-byte Folded Reload
+; C_CC_FMT-NEXT:    ld $ra, 8($sp) # 8-byte Folded Reload
+; C_CC_FMT-NEXT:    daddiu $sp, $sp, 16
+; C_CC_FMT-NEXT:    jr $ra
+; C_CC_FMT-NEXT:    nop
+;
+; CMP_CC_FMT-LABEL: call_retFP128:
+; CMP_CC_FMT:       # %bb.0: # %entry
+; CMP_CC_FMT-NEXT:    daddiu $sp, $sp, -16
+; CMP_CC_FMT-NEXT:    .cfi_def_cfa_offset 16
+; CMP_CC_FMT-NEXT:    sd $ra, 8($sp) # 8-byte Folded Spill
+; CMP_CC_FMT-NEXT:    sd $gp, 0($sp) # 8-byte Folded Spill
+; CMP_CC_FMT-NEXT:    .cfi_offset 31, -8
+; CMP_CC_FMT-NEXT:    .cfi_offset 28, -16
+; CMP_CC_FMT-NEXT:    lui $1, %hi(%neg(%gp_rel(call_retFP128)))
+; CMP_CC_FMT-NEXT:    daddu $1, $1, $25
+; CMP_CC_FMT-NEXT:    daddiu $gp, $1, %lo(%neg(%gp_rel(call_retFP128)))
+; CMP_CC_FMT-NEXT:    ld $25, %call16(bar)($gp)
+; CMP_CC_FMT-NEXT:    .reloc .Ltmp51, R_MIPS_JALR, bar
+; CMP_CC_FMT-NEXT:  .Ltmp51:
+; CMP_CC_FMT-NEXT:    jalrc $25
+; CMP_CC_FMT-NEXT:    daddiu $2, $zero, 0
+; CMP_CC_FMT-NEXT:    daddiu $4, $zero, 0
+; CMP_CC_FMT-NEXT:    ld $gp, 0($sp) # 8-byte Folded Reload
+; CMP_CC_FMT-NEXT:    ld $ra, 8($sp) # 8-byte Folded Reload
+; CMP_CC_FMT-NEXT:    daddiu $sp, $sp, 16
+; CMP_CC_FMT-NEXT:    jrc $ra
+entry:
+  call { i8, i128 } @bar()
+  ret fp128 0xL00000000000000000000000000000000
+}
 ;; NOTE: These prefixes are unused and the list is autogenerated. Do not add tests below this line:
 ; ALL: {{.*}}
 ; PRER6: {{.*}}