[PATCH] RISC-V: Remove DCE in VSETVL PASS

[PATCH] RISC-V: Remove DCE in VSETVL PASS

[juzhe.zhong]

From: Ju-Zhe Zhong <juzhe.zhong@rivai.ai>

gcc/ChangeLog:

        * config/riscv/riscv-vsetvl.cc (pass_vsetvl::done): Remove DCE.
        * config/riscv/t-riscv: Ditto.

---
 gcc/config/riscv/riscv-vsetvl.cc | 2 --
 gcc/config/riscv/t-riscv         | 2 +-
 2 files changed, 1 insertion(+), 3 deletions(-)

diff --git a/gcc/config/riscv/riscv-vsetvl.cc b/gcc/config/riscv/riscv-vsetvl.cc
index d494369a603..c2a8b44584d 100644
--- a/gcc/config/riscv/riscv-vsetvl.cc
+++ b/gcc/config/riscv/riscv-vsetvl.cc
@@ -87,7 +87,6 @@ along with GCC; see the file COPYING3.  If not see
 #include "predict.h"
 #include "profile-count.h"
 #include "riscv-vsetvl.h"
-#include "dce.h"
 
 using namespace rtl_ssa;
 using namespace riscv_vector;
@@ -2996,7 +2995,6 @@ pass_vsetvl::done (void)
 	cleanup_cfg (0);
       delete crtl->ssa;
       crtl->ssa = nullptr;
-      run_fast_dce ();
     }
   m_vector_manager->release ();
   delete m_vector_manager;
diff --git a/gcc/config/riscv/t-riscv b/gcc/config/riscv/t-riscv
index c95f4aff358..d30e0235356 100644
--- a/gcc/config/riscv/t-riscv
+++ b/gcc/config/riscv/t-riscv
@@ -54,7 +54,7 @@ riscv-c.o: $(srcdir)/config/riscv/riscv-c.cc $(CONFIG_H) $(SYSTEM_H) \
 riscv-vsetvl.o: $(srcdir)/config/riscv/riscv-vsetvl.cc \
   $(CONFIG_H) $(SYSTEM_H) coretypes.h $(TM_H) $(RTL_H) $(REGS_H) \
   $(TARGET_H) tree-pass.h df.h rtl-ssa.h cfgcleanup.h insn-config.h \
-  insn-attr.h insn-opinit.h tm-constrs.h cfgrtl.h cfganal.h lcm.h dce.h \
+  insn-attr.h insn-opinit.h tm-constrs.h cfgrtl.h cfganal.h lcm.h \
   predict.h profile-count.h $(srcdir)/config/riscv/riscv-vsetvl.h
 	$(COMPILER) -c $(ALL_COMPILERFLAGS) $(ALL_CPPFLAGS) $(INCLUDES) \
 		$(srcdir)/config/riscv/riscv-vsetvl.cc
-- 
2.36.3

Re: [PATCH] RISC-V: Remove DCE in VSETVL PASS

[Jeff Law]

On 1/17/23 19:53, juzhe.zhong@rivai.ai wrote:
> From: Ju-Zhe Zhong <juzhe.zhong@rivai.ai>
> 
> gcc/ChangeLog:
> 
>          * config/riscv/riscv-vsetvl.cc (pass_vsetvl::done): Remove DCE.
>          * config/riscv/t-riscv: Ditto.
OK.  Presumably this is because the pass is now placed before DCE.

Jeff