The error in both cases is caused by the same reason: the target IR, MulReductionVI, is not matched.
This is because the match_rule_supported_vector in riscv_v.ad is missing a break. If the if condition in `case MulReductionVI` evaluates to false, the loop will not exit until the `return UseZvfh`.

Failed IR tests:
compiler/loopopts/superword/ProdRed_Int.java
compiler/loopopts/superword/RedTest_int.java

Error log of ProdRed_Int.java：
```
One or more @IR rules failed:

Failed IR Rules (1) of Methods (1)
----------------------------------
1) Method "public static int compiler.loopopts.superword.ProdRed_Int.prodReductionImplement(int[],int[],int)" - [Failed IR rules: 1]:
   * @IR rule 3: "@compiler.lib.ir_framework.IR(phase={DEFAULT}, applyIfPlatformAnd={}, applyIfCPUFeatureOr={}, counts={"_#MUL_REDUCTION_VI#_", ">= 1", "_#MUL_REDUCTION_VI#_", "<= 2"}, failOn={}, applyIfPlatform={}, applyIfPlatformOr={}, applyIfOr={}, applyIfCPUFeatureAnd={}, applyIf={}, applyIfCPUFeature={"rvv", "true"}, applyIfAnd={"SuperWordReductions", "true", "LoopMaxUnroll", ">= 8"}, applyIfNot={})"
     > Phase "PrintIdeal":
       - counts: Graph contains wrong number of nodes:
         * Constraint 1: "(\\d+(\\s){2}(MulReductionVI.*)+(\\s){2}===.*)"
           - Failed comparison: [found] 0 >= 1 [given]
           - No nodes matched!

>>> Check stdout for compilation output of the failed methods

One or more @IR rules failed:

Failed IR Rules (1) of Methods (1)
----------------------------------
1) Method "public static int compiler.loopopts.superword.ProdRed_Int.prodReductionImplement(int[],int[],int)" - [Failed IR rules: 1]:
   * @IR rule 3: "@compiler.lib.ir_framework.IR(phase={DEFAULT}, applyIfPlatformAnd={}, applyIfCPUFeatureOr={}, counts={"_#MUL_REDUCTION_VI#_", ">= 1", "_#MUL_REDUCTION_VI#_", "<= 2"}, failOn={}, applyIfPlatform={}, applyIfPlatformOr={}, applyIfOr={}, applyIfCPUFeatureAnd={}, applyIf={}, applyIfCPUFeature={"rvv", "true"}, applyIfAnd={"SuperWordReductions", "true", "LoopMaxUnroll", ">= 8"}, applyIfNot={})"
     > Phase "PrintIdeal":
       - counts: Graph contains wrong number of nodes:
         * Constraint 1: "(\\d+(\\s){2}(MulReductionVI.*)+(\\s){2}===.*)"
           - Failed comparison: [found] 0 >= 1 [given]
           - No nodes matched!

>>> Check stdout for compilation output of the failed methods
```