change unit of --param max-gcse-memory to kB

This changes it from bytes to kB since its value is limited to
2147483648.

2021-01-29  Richard Biener  <rguenther@suse.de>

	* doc/invoke.texi (--param max-gcse-memory): Document unit
	of size.
	* gcse.c (gcse_or_cprop_is_too_expensive): Adjust.
	* params.opt (--param max-gcse-memory): Adjust default and
	document unit of size.

diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index d9e49c4..a89d385 100644 (file)
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -13075,7 +13075,7 @@ should be removed when the delay slot code is rewritten to maintain the
 control-flow graph.
 
 @item max-gcse-memory
-The approximate maximum amount of memory that can be allocated in
+The approximate maximum amount of memory in @code{kB} that can be allocated in
 order to perform the global common subexpression elimination
 optimization.  If more memory than specified is required, the
 optimization is not done.

diff --git a/gcc/gcse.c b/gcc/gcse.c
index 29c9f90..2c81fe4 100644 (file)
--- a/gcc/gcse.c
+++ b/gcc/gcse.c
@@ -4007,14 +4007,14 @@ gcse_or_cprop_is_too_expensive (const char *pass)
 
   /* If allocating memory for the dataflow bitmaps would take up too much
      storage it's better just to disable the optimization.  */
-  if (memory_request > (unsigned HOST_WIDE_INT)param_max_gcse_memory)
+  if (memory_request / 1024 > (unsigned HOST_WIDE_INT)param_max_gcse_memory)
     {
       warning (OPT_Wdisabled_optimization,
               "%s: %d basic blocks and %d registers; "
               "increase %<--param max-gcse-memory%> above "
               HOST_WIDE_INT_PRINT_UNSIGNED,
               pass, n_basic_blocks_for_fn (cfun), max_reg_num (),
-              memory_request);
+              memory_request / 1024);
 
       return true;
     }

diff --git a/gcc/params.opt b/gcc/params.opt
index cfed980..dff8a33 100644 (file)
--- a/gcc/params.opt
+++ b/gcc/params.opt
@@ -514,8 +514,8 @@ Common Joined UInteger Var(param_max_gcse_insertion_ratio) Init(20) Param Optimi
 The maximum ratio of insertions to deletions of expressions in GCSE.
 
 -param=max-gcse-memory=
-Common Joined UInteger Var(param_max_gcse_memory) Init(134217728) Param Optimization
-The maximum amount of memory to be allocated by GCSE.
+Common Joined UInteger Var(param_max_gcse_memory) Init(131072) Param Optimization
+The maximum amount of memory to be allocated by GCSE, in kilobytes.
 
 -param=max-goto-duplication-insns=
 Common Joined UInteger Var(param_max_goto_duplication_insns) Init(8) Param Optimization