[gcc(refs/vendors/riscv/heads/gcc-15-with-riscv-opts)] RISC-V: Avoid division by zero in check_builtin_call [PR120436].

[Jeff Law]

https://gcc.gnu.org/g:d39c7003c84508f38abe6713ece81b01cc77a5a6

commit d39c7003c84508f38abe6713ece81b01cc77a5a6
Author: Robin Dapp <rdapp@ventanamicro.com>
Date:   Mon May 26 16:16:36 2025 +0200

    RISC-V: Avoid division by zero in check_builtin_call [PR120436].
    
    In check_builtin_call we eventually perform a division by zero when no
    vector modes are present.  This patch just avoids the division in that
    case.
    
            PR target/120436
    
    gcc/ChangeLog:
    
            * config/riscv/riscv-vector-builtins-shapes.cc (struct vset_def):
            Avoid division by zero.
            (struct vget_def): Ditto.
            * config/riscv/riscv-vector-builtins.h (struct function_group_info):
            Use required_extensions_specified instead of duplicating code.
    
    gcc/testsuite/ChangeLog:
    
            * gcc.target/riscv/rvv/base/pr120436.c: New test.
    
    (cherry picked from commit 6ccf845d9fa157e7ebcf2c589a9fc5d8f298961f)

Diff:
---
 gcc/config/riscv/riscv-vector-builtins-shapes.cc   |  4 +++
 gcc/config/riscv/riscv-vector-builtins.h           | 40 +---------------------
 gcc/testsuite/gcc.target/riscv/rvv/base/pr120436.c | 16 +++++++++
 3 files changed, 21 insertions(+), 39 deletions(-)

diff --git a/gcc/config/riscv/riscv-vector-builtins-shapes.cc b/gcc/config/riscv/riscv-vector-builtins-shapes.cc
index b855d4c5fa5a..9832eb9e3d1b 100644
--- a/gcc/config/riscv/riscv-vector-builtins-shapes.cc
+++ b/gcc/config/riscv/riscv-vector-builtins-shapes.cc
@@ -908,6 +908,8 @@ struct vset_def : public build_base
   {
     poly_int64 outer_size = GET_MODE_SIZE (c.arg_mode (0));
     poly_int64 inner_size = GET_MODE_SIZE (c.arg_mode (2));
+    if (maybe_eq (inner_size, 0))
+      return false;
     unsigned int nvecs = exact_div (outer_size, inner_size).to_constant ();
     return c.require_immediate (1, 0, nvecs - 1);
   }
@@ -920,6 +922,8 @@ struct vget_def : public misc_def
   {
     poly_int64 outer_size = GET_MODE_SIZE (c.arg_mode (0));
     poly_int64 inner_size = GET_MODE_SIZE (c.ret_mode ());
+    if (maybe_eq (inner_size, 0))
+      return false;
     unsigned int nvecs = exact_div (outer_size, inner_size).to_constant ();
     return c.require_immediate (1, 0, nvecs - 1);
   }
diff --git a/gcc/config/riscv/riscv-vector-builtins.h b/gcc/config/riscv/riscv-vector-builtins.h
index ffc289364b06..1f2587ab6afa 100644
--- a/gcc/config/riscv/riscv-vector-builtins.h
+++ b/gcc/config/riscv/riscv-vector-builtins.h
@@ -331,45 +331,7 @@ struct function_group_info
   /* Return true if required extension is enabled */
   bool match (required_ext ext_value) const
   {
-    switch (ext_value)
-    {
-      case VECTOR_EXT:
-        return TARGET_VECTOR;
-      case ZVBB_EXT:
-        return TARGET_ZVBB;
-      case ZVBB_OR_ZVKB_EXT:
-        return (TARGET_ZVBB || TARGET_ZVKB);
-      case ZVBC_EXT:
-        return TARGET_ZVBC;
-      case ZVKG_EXT:
-        return TARGET_ZVKG;
-      case ZVKNED_EXT:
-        return TARGET_ZVKNED;
-      case ZVKNHA_OR_ZVKNHB_EXT:
-        return (TARGET_ZVKNHA || TARGET_ZVKNHB);
-      case ZVKNHB_EXT:
-        return TARGET_ZVKNHB;
-      case ZVKSED_EXT:
-        return TARGET_ZVKSED;
-      case ZVKSH_EXT:
-        return TARGET_ZVKSH;
-      case XTHEADVECTOR_EXT:
-	return TARGET_XTHEADVECTOR;
-      case ZVFBFMIN_EXT:
-	return TARGET_ZVFBFMIN;
-      case ZVFBFWMA_EXT:
-	return TARGET_ZVFBFWMA;
-      case XSFVQMACCQOQ_EXT:
-	return TARGET_XSFVQMACCQOQ;
-      case XSFVQMACCDOD_EXT:
-	return TARGET_XSFVQMACCDOD;
-      case XSFVFNRCLIPXFQF_EXT:
-	return TARGET_XSFVFNRCLIPXFQF;
-      case XSFVCP_EXT:
-	return TARGET_XSFVCP;
-      default:
-        gcc_unreachable ();
-    }
+    return required_extensions_specified (ext_value);
   }
   /* The base name, as a string.  */
   const char *base_name;
diff --git a/gcc/testsuite/gcc.target/riscv/rvv/base/pr120436.c b/gcc/testsuite/gcc.target/riscv/rvv/base/pr120436.c
new file mode 100644
index 000000000000..d22091e59490
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/rvv/base/pr120436.c
@@ -0,0 +1,16 @@
+/* { dg-do compile } */
+/* { dg-options "-march=rv64gc -mabi=lp64d -O0" } */
+
+/* Use -O0 as otherwise the unused intrinsics get
+   optimized away.  We used to ICE here instead of
+   emitting an error.  */
+
+#include "riscv_vector.h"
+
+void
+clean_subreg (int32_t *in, int32_t *out, size_t m) /* { dg-error {this operation requires the RVV ISA extension} } */
+{
+  vint16m8_t v24, v8, v16;
+  vint32m8_t result = __riscv_vle32_v_i32m8 (in, 32); /* { dg-error {built-in function '__riscv_vle32_v_i32m8\(in, 32\)' requires the 'v' ISA extension} } */
+  vint32m1_t v0 = __riscv_vget_v_i32m8_i32m1 (result, 0);
+}