[llvm] 9fba20b - [SiFive][RISCV] Remove VMConstraint from XSfvqmaccqoq and XSfvfwmaccqqq instructions. (#142914)

[via llvm-commits]

Author: Craig Topper
Date: 2025-06-05T07:05:23-07:00
New Revision: 9fba20bfacc878bc89b89c1ff44805c5f8a142df

URL: https://github.com/llvm/llvm-project/commit/9fba20bfacc878bc89b89c1ff44805c5f8a142df
DIFF: https://github.com/llvm/llvm-project/commit/9fba20bfacc878bc89b89c1ff44805c5f8a142df.diff

LOG: [SiFive][RISCV] Remove VMConstraint from XSfvqmaccqoq and XSfvfwmaccqqq instructions. (#142914)

These instructions don't have a mask operand. The VMConstraint would
cause an assertion if V0 is used as the destination and the last
register isn't V0.

Added: 
    

Modified: 
    llvm/lib/Target/RISCV/RISCVInstrFormats.td
    llvm/lib/Target/RISCV/RISCVInstrInfoXSf.td
    llvm/test/MC/RISCV/rvv/xsfvfwmacc.s
    llvm/test/MC/RISCV/rvv/xsfvqmacc.s

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Target/RISCV/RISCVInstrFormats.td b/llvm/lib/Target/RISCV/RISCVInstrFormats.td
index 8d56637d8b281..088a6923fadb1 100644
--- a/llvm/lib/Target/RISCV/RISCVInstrFormats.td
+++ b/llvm/lib/Target/RISCV/RISCVInstrFormats.td
@@ -99,6 +99,8 @@ def VMConstraint  : RISCVVConstraint<0b100>;
 //
 // * vcompress: The destination vector register group cannot overlap the
 // source vector register group or the source mask register
+def WidenVNoMask : RISCVVConstraint<!or(VS2Constraint.Value,
+                                        VS1Constraint.Value)>;
 def WidenV       : RISCVVConstraint<!or(VS2Constraint.Value,
                                         VS1Constraint.Value,
                                         VMConstraint.Value)>;

diff  --git a/llvm/lib/Target/RISCV/RISCVInstrInfoXSf.td b/llvm/lib/Target/RISCV/RISCVInstrInfoXSf.td
index 6981daa75d092..affe3a8476753 100644
--- a/llvm/lib/Target/RISCV/RISCVInstrInfoXSf.td
+++ b/llvm/lib/Target/RISCV/RISCVInstrInfoXSf.td
@@ -208,7 +208,7 @@ let Predicates = [HasVendorXSfvqmaccdod], DecoderNamespace = "XSfvector",
 }
 
 let Predicates = [HasVendorXSfvqmaccqoq], DecoderNamespace = "XSfvector",
-    DestEEW = EEWSEWx4, RVVConstraint=WidenV in {
+    DestEEW = EEWSEWx4, RVVConstraint=WidenVNoMask in {
   def VQMACCU_4x8x4  : CustomSiFiveVMACC<0b111100, OPMVV, "sf.vqmaccu.4x8x4">;
   def VQMACC_4x8x4   : CustomSiFiveVMACC<0b111101, OPMVV, "sf.vqmacc.4x8x4">;
   def VQMACCUS_4x8x4 : CustomSiFiveVMACC<0b111110, OPMVV, "sf.vqmaccus.4x8x4">;
@@ -216,7 +216,7 @@ let Predicates = [HasVendorXSfvqmaccqoq], DecoderNamespace = "XSfvector",
 }
 
 let Predicates = [HasVendorXSfvfwmaccqqq], DecoderNamespace = "XSfvector",
-    DestEEW = EEWSEWx2, RVVConstraint=WidenV in {
+    DestEEW = EEWSEWx2, RVVConstraint=WidenVNoMask in {
   def VFWMACC_4x4x4 : CustomSiFiveVMACC<0b111100, OPFVV, "sf.vfwmacc.4x4x4">;
 }
 

diff  --git a/llvm/test/MC/RISCV/rvv/xsfvfwmacc.s b/llvm/test/MC/RISCV/rvv/xsfvfwmacc.s
index a9843c350fc80..5168c42da70d9 100644
--- a/llvm/test/MC/RISCV/rvv/xsfvfwmacc.s
+++ b/llvm/test/MC/RISCV/rvv/xsfvfwmacc.s
@@ -13,3 +13,9 @@ sf.vfwmacc.4x4x4 v8, v4, v20
 # CHECK-ENCODING: [0x5b,0x14,0x42,0xf3]
 # CHECK-ERROR: instruction requires the following: 'XSfvfwmaccqqq' (SiFive Matrix Multiply Accumulate Instruction and 4-by-4))
 # CHECK-UNKNOWN: f342145b <unknown>
+
+sf.vfwmacc.4x4x4 v0, v4, v20
+# CHECK-INST: sf.vfwmacc.4x4x4 v0, v4, v20
+# CHECK-ENCODING: [0x5b,0x10,0x42,0xf3]
+# CHECK-ERROR: instruction requires the following: 'XSfvfwmaccqqq' (SiFive Matrix Multiply Accumulate Instruction and 4-by-4))
+# CHECK-UNKNOWN: f342105b <unknown>

diff  --git a/llvm/test/MC/RISCV/rvv/xsfvqmacc.s b/llvm/test/MC/RISCV/rvv/xsfvqmacc.s
index 81703c847d74e..d7d3cba41cbc6 100644
--- a/llvm/test/MC/RISCV/rvv/xsfvqmacc.s
+++ b/llvm/test/MC/RISCV/rvv/xsfvqmacc.s
@@ -55,3 +55,9 @@ sf.vqmaccsu.4x8x4 v8, v4, v20
 # CHECK-ENCODING: [0x5b,0x24,0x42,0xff]
 # CHECK-ERROR: instruction requires the following: 'XSfvqmaccqoq' (SiFive Int8 Matrix Multiplication Instructions (4-by-8 and 8-by-4))
 # CHECK-UNKNOWN: ff42245b <unknown>
+
+sf.vqmaccu.4x8x4 v0, v4, v20
+# CHECK-INST: sf.vqmaccu.4x8x4 v0, v4, v20
+# CHECK-ENCODING: [0x5b,0x20,0x42,0xf3]
+# CHECK-ERROR: instruction requires the following: 'XSfvqmaccqoq' (SiFive Int8 Matrix Multiplication Instructions (4-by-8 and 8-by-4))
+# CHECK-UNKNOWN: f342205b <unknown>