[gcc(refs/vendors/riscv/heads/gcc-14-with-riscv-opts)] [RISC-V][V2] Fix incorrect if-then-else nesting of Zbs usage in constant synthesis

[Jeff Law via Gcc-cvs]

https://gcc.gnu.org/g:ad8a3dc0a14bd316a9f1e06bd55f81d27f190d6f

commit ad8a3dc0a14bd316a9f1e06bd55f81d27f190d6f
Author: Jeff Law <j...@ventanamicro.com>
Date:   Wed May 8 13:44:00 2024 -0600

    [RISC-V][V2] Fix incorrect if-then-else nesting of Zbs usage in constant 
synthesis
    
    Reposting without the patch that ignores whitespace.  The CI system doesn't
    like including both patches, that'll generate a failure to apply and none of
    the tests actually get run.
    
    So I managed to goof the if-then-else level of the bseti bits last week.  
They
    were supposed to be a last ditch effort to improve the result, but ended up
    inside a conditional where they don't really belong.  I almost always use 
Zba,
    Zbb and Zbs together, so it slipped by.
    
    So it's NFC if you always test with Zbb and Zbs enabled together.  But if 
you
    enabled Zbs without Zbb you'd see a failure to use bseti.
    
    gcc/
            * config/riscv/riscv.cc (riscv_build_integer_1): Fix incorrect
            if-then-else nesting of Zbs code.
    
    (cherry picked from commit 1c234097487927a4388ddcc690b63597bb3a90dc)

Diff:
---
 gcc/config/riscv/riscv.cc | 81 ++++++++++++++++++++++++-----------------------
 1 file changed, 41 insertions(+), 40 deletions(-)

diff --git a/gcc/config/riscv/riscv.cc b/gcc/config/riscv/riscv.cc
index eaf96b2ef7a..49ae12f8ee0 100644
--- a/gcc/config/riscv/riscv.cc
+++ b/gcc/config/riscv/riscv.cc
@@ -887,50 +887,51 @@ riscv_build_integer_1 (struct riscv_integer_op 
codes[RISCV_MAX_INTEGER_OPS],
          codes[1].use_uw = false;
          cost = 2;
        }
-      /* Final cases, particularly focused on bseti.  */
-      else if (cost > 2 && TARGET_ZBS)
-       {
-         int i = 0;
+    }
 
-         /* First handle any bits set by LUI.  Be careful of the
-            SImode sign bit!.  */
-         if (value & 0x7ffff800)
-           {
-             alt_codes[i].code = (i == 0 ? UNKNOWN : IOR);
-             alt_codes[i].value = value & 0x7ffff800;
-             alt_codes[i].use_uw = false;
-             value &= ~0x7ffff800;
-             i++;
-           }
+  /* Final cases, particularly focused on bseti.  */
+  if (cost > 2 && TARGET_ZBS)
+    {
+      int i = 0;
 
-         /* Next, any bits we can handle with addi.  */
-         if (value & 0x7ff)
-           {
-             alt_codes[i].code = (i == 0 ? UNKNOWN : PLUS);
-             alt_codes[i].value = value & 0x7ff;
-             alt_codes[i].use_uw = false;
-             value &= ~0x7ff;
-             i++;
-           }
+      /* First handle any bits set by LUI.  Be careful of the
+        SImode sign bit!.  */
+      if (value & 0x7ffff800)
+       {
+         alt_codes[i].code = (i == 0 ? UNKNOWN : IOR);
+         alt_codes[i].value = value & 0x7ffff800;
+         alt_codes[i].use_uw = false;
+         value &= ~0x7ffff800;
+          i++;
+       }
 
-         /* And any residuals with bseti.  */
-         while (i < cost && value)
-           {
-             HOST_WIDE_INT bit = ctz_hwi (value);
-             alt_codes[i].code = (i == 0 ? UNKNOWN : IOR);
-             alt_codes[i].value = 1UL << bit;
-             alt_codes[i].use_uw = false;
-             value &= ~(1ULL << bit);
-             i++;
-           }
+      /* Next, any bits we can handle with addi.  */
+      if (value & 0x7ff)
+       {
+         alt_codes[i].code = (i == 0 ? UNKNOWN : PLUS);
+         alt_codes[i].value = value & 0x7ff;
+         alt_codes[i].use_uw = false;
+         value &= ~0x7ff;
+         i++;
+       }
 
-         /* If LUI+ADDI+BSETI resulted in a more efficient
-            sequence, then use it.  */
-         if (i < cost)
-           {
-             memcpy (codes, alt_codes, sizeof (alt_codes));
-             cost = i;
-           }
+      /* And any residuals with bseti.  */
+      while (i < cost && value)
+       {
+         HOST_WIDE_INT bit = ctz_hwi (value);
+         alt_codes[i].code = (i == 0 ? UNKNOWN : IOR);
+         alt_codes[i].value = 1UL << bit;
+         alt_codes[i].use_uw = false;
+         value &= ~(1ULL << bit);
+         i++;
+       }
+
+      /* If LUI+ADDI+BSETI resulted in a more efficient
+        sequence, then use it.  */
+      if (i < cost)
+       {
+         memcpy (codes, alt_codes, sizeof (alt_codes));
+         cost = i;
        }
     }