diff options
Diffstat (limited to 'meta-xilinx-bsp/recipes-microblaze/gcc/gcc-8/0027-Patch-rtl-Optimization-Better-register-pressure-esti.patch')
| -rw-r--r-- | meta-xilinx-bsp/recipes-microblaze/gcc/gcc-8/0027-Patch-rtl-Optimization-Better-register-pressure-esti.patch | 142 |
1 files changed, 0 insertions, 142 deletions
diff --git a/meta-xilinx-bsp/recipes-microblaze/gcc/gcc-8/0027-Patch-rtl-Optimization-Better-register-pressure-esti.patch b/meta-xilinx-bsp/recipes-microblaze/gcc/gcc-8/0027-Patch-rtl-Optimization-Better-register-pressure-esti.patch deleted file mode 100644 index 95b9b2aa..00000000 --- a/meta-xilinx-bsp/recipes-microblaze/gcc/gcc-8/0027-Patch-rtl-Optimization-Better-register-pressure-esti.patch +++ /dev/null @@ -1,142 +0,0 @@ -From 5147c831c6a78d9b95138b679bb2ca7624abc3a1 Mon Sep 17 00:00:00 2001 -From: Mahesh Bodapati <mbodapat@xilinx.com> -Date: Wed, 18 Jan 2017 11:08:40 +0530 -Subject: [PATCH 27/54] [Patch,rtl Optimization]: Better register pressure - estimate for loop . .invariant code motion - -Calculate the loop liveness used for regs for calculating the register pressure -in the cost estimation. Loop liveness is based on the following properties. -We only need to find the set of objects that are live at the birth or the header -of the loop. We don't need to calculate the live through the loop by considering -live in and live out of all the basic blocks of the loop. This is based on the -point that the set of objects that are live-in at the birth or header of the loop -will be live-in at every node in the loop. - -If a v live is out at the header of the loop then the variable is live-in at every node -in the loop. To prove this, consider a loop L with header h such that the variable v -defined at d is live-in at h. Since v is live at h, d is not part of L. This follows i -from the dominance property, i.e. h is strictly dominated by d. Furthermore, there -exists a path from h to a use of v which does not go through d. For every node p in -the loop, since the loop is strongly connected and node is a component of the CFG, -there exists a path, consisting only of nodes of L from p to h. Concatenating these -two paths proves that v is live-in and live-out of p. - -Calculate the live-out and live-in for the exit edge of the loop. This patch considers -liveness for not only the loop latch but also the liveness outside the loops. - -ChangeLog: -2016-01-22 Ajit Agarwal <ajitkum@xilinx.com> - - * loop-invariant.c - (find_invariants_to_move): Add the logic of regs_used based - on liveness. - * cfgloopanal.c - (estimate_reg_pressure_cost): Update the heuristics in presence - of call_p. - -Signed-off-by:Ajit Agarwal ajitkum@xilinx.com. ---- - gcc/cfgloopanal.c | 4 +++- - gcc/loop-invariant.c | 63 +++++++++++++++++++++++++++++++++++++++------------- - 2 files changed, 50 insertions(+), 17 deletions(-) - -diff --git a/gcc/cfgloopanal.c b/gcc/cfgloopanal.c -index 3af0b2d..123dc6b 100644 ---- a/gcc/cfgloopanal.c -+++ b/gcc/cfgloopanal.c -@@ -411,7 +411,9 @@ estimate_reg_pressure_cost (unsigned n_new, unsigned n_old, bool speed, - if (regs_needed + target_res_regs <= available_regs) - return 0; - -- if (regs_needed <= available_regs) -+ if ((regs_needed <= available_regs) -+ || (call_p && (regs_needed <= -+ (available_regs + target_clobbered_regs)))) - /* If we are close to running out of registers, try to preserve - them. */ - cost = target_reg_cost [speed] * n_new; -diff --git a/gcc/loop-invariant.c b/gcc/loop-invariant.c -index 8e22ca0..c9ec8df 100644 ---- a/gcc/loop-invariant.c -+++ b/gcc/loop-invariant.c -@@ -1520,7 +1520,7 @@ gain_for_invariant (struct invariant *inv, unsigned *regs_needed, - size_cost = 0; - } - -- return comp_cost - size_cost; -+ return comp_cost - size_cost + 1; - } - - /* Finds invariant with best gain for moving. Returns the gain, stores -@@ -1614,22 +1614,53 @@ find_invariants_to_move (bool speed, bool call_p) - /* REGS_USED is actually never used when the flag is on. */ - regs_used = 0; - else -- /* We do not really do a good job in estimating number of -- registers used; we put some initial bound here to stand for -- induction variables etc. that we do not detect. */ -+ /* The logic used in estimating the number of regs_used is changed. -+ Now it will be based on liveness of the loop. */ - { -- unsigned int n_regs = DF_REG_SIZE (df); -- -- regs_used = 2; -- -- for (i = 0; i < n_regs; i++) -- { -- if (!DF_REGNO_FIRST_DEF (i) && DF_REGNO_LAST_USE (i)) -- { -- /* This is a value that is used but not changed inside loop. */ -- regs_used++; -- } -- } -+ int i; -+ edge e; -+ vec<edge> edges; -+ bitmap_head regs_live; -+ -+ bitmap_initialize (®s_live, ®_obstack); -+ edges = get_loop_exit_edges (curr_loop); -+ -+ /* Loop liveness is based on the following properties. -+ We only need to find the set of objects that are live at the -+ birth or the header of the loop. -+ We don't need to calculate the live through the loop considering -+ live-in and live-out of all the basic blocks of the loop. This is -+ based on the point that the set of objects that are live-in at the -+ birth or header of the loop will be live-in at every block in the -+ loop. -+ -+ If a v live out at the header of the loop then the variable is -+ live-in at every node in the Loop. To prove this, consider a loop -+ L with header h such that the variable v defined at d is live-in -+ at h. Since v is live at h, d is not part of L. This follows from -+ the dominance property, i.e. h is strictly dominated by d. Furthermore, -+ there exists a path from h to a use of v which does not go through d. -+ For every node of the loop, p, since the loop is strongly connected -+ component of the CFG, there exists a path, consisting only of nodes -+ of L from p to h. Concatenating these two paths prove that v is -+ live-in and live-out of p. */ -+ -+ bitmap_ior_into (®s_live, DF_LR_IN (curr_loop->header)); -+ bitmap_ior_into (®s_live, DF_LR_OUT (curr_loop->header)); -+ -+ /* Calculate the live-out and live-in for the exit edge of the loop. -+ This considers liveness for not only the loop latch but also the -+ liveness outside the loops. */ -+ -+ FOR_EACH_VEC_ELT (edges, i, e) -+ { -+ bitmap_ior_into (®s_live, DF_LR_OUT (e->src)); -+ bitmap_ior_into (®s_live, DF_LR_IN (e->dest)); -+ } -+ -+ regs_used = bitmap_count_bits (®s_live) + 2; -+ bitmap_clear (®s_live); -+ edges.release (); - } - - if (! flag_ira_loop_pressure) --- -2.7.4 - |