[PATCH] D72134: [RISCV] Fix test for inline asm z constraint modifier

[Luís Marques via Phabricator via llvm-commits]

luismarques created this revision.
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The inline assembly `z` constraint modifier is handled by the following code in `RISCVAsmPrinter.cpp`:

  case 'z':      // Print zero register if zero, regular printing otherwise.
    if (MO.isImm() && MO.getImm() == 0) {
      OS << RISCVInstPrinter::getRegisterName(RISCV::X0);
      return false;
    }
    break;

Because the test was using an `r` operand constraint, the condition `MO.isImm()` wouldn't trigger, so we didn't actually have a test for the `z` modifier. The `zero` we were seeing in the test CHECK line was unrelated to the modifier, and would even persist if the modifier wasn't used.

This patch changes the relevant tests to use an `i` constraint, which does trigger the `z` constraint modifier handling code.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D72134

Files:
  llvm/test/CodeGen/RISCV/inline-asm.ll


Index: llvm/test/CodeGen/RISCV/inline-asm.ll
===================================================================
--- llvm/test/CodeGen/RISCV/inline-asm.ll
+++ llvm/test/CodeGen/RISCV/inline-asm.ll
@@ -189,27 +189,25 @@
 ; RV64I-NEXT:    add a0, a0, zero
 ; RV64I-NEXT:    #NO_APP
 ; RV64I-NEXT:    ret
-  %1 = tail call i32 asm "add $0, $1, ${2:z}", "=r,r,r"(i32 %a, i32 0)
+  %1 = tail call i32 asm "add $0, $1, ${2:z}", "=r,r,i"(i32 %a, i32 0)
   ret i32 %1
 }
 
 define i32 @modifier_z_nonzero(i32 %a) nounwind {
 ; RV32I-LABEL: modifier_z_nonzero:
 ; RV32I:       # %bb.0:
-; RV32I-NEXT:    addi a1, zero, 1
 ; RV32I-NEXT:    #APP
-; RV32I-NEXT:    add a0, a0, a1
+; RV32I-NEXT:    add a0, a0, 1
 ; RV32I-NEXT:    #NO_APP
 ; RV32I-NEXT:    ret
 ;
 ; RV64I-LABEL: modifier_z_nonzero:
 ; RV64I:       # %bb.0:
-; RV64I-NEXT:    addi a1, zero, 1
 ; RV64I-NEXT:    #APP
-; RV64I-NEXT:    add a0, a0, a1
+; RV64I-NEXT:    add a0, a0, 1
 ; RV64I-NEXT:    #NO_APP
 ; RV64I-NEXT:    ret
-  %1 = tail call i32 asm "add $0, $1, ${2:z}", "=r,r,r"(i32 %a, i32 1)
+  %1 = tail call i32 asm "add $0, $1, ${2:z}", "=r,r,i"(i32 %a, i32 1)
   ret i32 %1
 }
 


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